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A review of β-glucans as a growth promoter and antibiotic alternative against enteric pathogens in poultry
World’s Poultry Science Journal
Abstract
The emergence of microbial challenges in commercial poultry farming causes significant economic losses. Vaccination is effective in preventing diseases of single aetiology while antibiotics have an advantage over vaccination in controlling diseases of multiple aetiologies. As the occurrence of antibiotic resistance is a serious problem, there is increased pressure on producers to reduce antibiotic use in poultry production. Therefore, it is essential to use alternative substances to cope with microbial challenges in commercial poultry farming. This review will focus on the role of β-glucans originating from yeast cell wall (YCW) as a growth promoter and antibiotic alternative. β-glucans have the ability to modulate the intestinal morphology by increasing the number of goblet cells, mucin expression and cells expressing secretory IgA (sIgA) with increased sIgA in the intestinal lumen and decreased bacterial translocation to different organs. β-glucans also increase the gene expression of tight junction (TJ) proteins which maintain the integrity of the intestinal wall in broiler chickens. However, further studies are required to optimise the dosage and source of β-glucans to determine effects on growth performance and mechanisms against enteric pathogens.
... After fermentation process, the yeast cells were washed, centrifuged, heated, and dried (Håkenåsen, 2017). There are two yeast extraction production processes: autolysis, using the yeast's own enzymes or hydrolysis, using added exogenous enzymes (Anwar et al., 2017;Alves et al., 2021). Once the lysis process is complete, the yeast extract (the intracellular soluble fraction) and the cell walls are separated using centrifugation before being dried (Bzducha-Wróbel et al., 2014). ...
... Although autolysis is cheaper than hydrolysis, smaller fractions of yeast are produced using hydrolysis (Mohd Azhar et al., 2017); consequently, they contain higher levels of yeast nucleotides in the extract (Anwar et al., 2017;Mohd Azhar et al., 2017). Avramia and Amariei (2021) reported that yeast produced using autolysis contains MOS on the outside, while hydrolyzed yeast contains a mixture of MOS and β-glucans on the outside. ...
... Yeast cell wall compositionSources:Bowman and Free, 2006;Shaun et al., 2006;Ponton, 2008;Anwar et al., 2017;Garcia-Rubio et al., 2020;Lee et al., 2021 ...
... Aside from its positive effects on the immune system, β-glucans also have beneficial effects on the gut. It can increase the number of Goblet cells and stimulates cells related to secretory IgA (sIgA) resulting from the increased number of sIgA in the intestinal lumen (Anwar et al., 2017)there is increased pressure on producers to reduce antibiotic use in poultry production. Therefore, it is essential to use alternative substances to cope with microbial challenges in commercial poultry farming. ...
... In poultry, supplementation of β-glucans protects against a number of economicallyimportant pathogens, such as Escherichia coli, Salmonella enterica, and Eimeria species and improves gut health and increases disease resistance (Anwar et al., 2017;Omara et al., 2021;Shao et al., 2013)3/1,6-glucan on gut morphology, intestinal epithelial tight junctions, and bacterial translocation of broiler chickens challenged with Salmonella enterica serovar Typhimurium. Ninety Salmonella-free Arbor Acre male broiler chickens were randomly divided into 3 groups: negative control group (NC. ...
... β-glucans as an alternative to antibiotics the in-poultry industry has not yet been deeply examined (Anwar et al., 2017) there is increased pressure on producers to reduce antibiotic use in poultry production. Therefore, it is essential to use alternative substances to cope with microbial challenges in commercial poultry farming. ...
Poultry as an industry was continuously growing worldwide and demands for poultry meats were markedly increasing. However, the limited use of antibiotics as treatments and as growth promoters became a serious problem due to the emergence of antibiotic resistance. Therefore, exploring other alternatives such as using feed additives like beta-glucans were widely studied and used to meet the demands of the consumers. This review focused on the different functions and effects of beta-glucans in poultry. Beta-glucans were known to have immunomodulation effects by upregulating the cytokines and other immune cells to overcome a disease. Aside from its immunomodulation effects, it can also increase the intestinal villi and crypts. Furthermore, an increase in growth performance was also observed. This evidence is promising but further research is required to properly establish the various functions of beta-glucans in poultry.
... Aside from its positive effects on the immune system, β-glucans also have beneficial effects on the gut. It can increase the number of Goblet cells and stimulates cells related to secretory IgA (sIgA) resulting from the increased number of sIgA in the intestinal lumen (Anwar et al., 2017)there is increased pressure on producers to reduce antibiotic use in poultry production. Therefore, it is essential to use alternative substances to cope with microbial challenges in commercial poultry farming. ...
... In poultry, supplementation of β-glucans protects against a number of economicallyimportant pathogens, such as Escherichia coli, Salmonella enterica, and Eimeria species and improves gut health and increases disease resistance (Anwar et al., 2017;Omara et al., 2021;Shao et al., 2013)3/1,6-glucan on gut morphology, intestinal epithelial tight junctions, and bacterial translocation of broiler chickens challenged with Salmonella enterica serovar Typhimurium. Ninety Salmonella-free Arbor Acre male broiler chickens were randomly divided into 3 groups: negative control group (NC. ...
... β-glucans as an alternative to antibiotics the in-poultry industry has not yet been deeply examined (Anwar et al., 2017) there is increased pressure on producers to reduce antibiotic use in poultry production. Therefore, it is essential to use alternative substances to cope with microbial challenges in commercial poultry farming. ...
Poultry as an industry was continuously growing worldwide and demand for poultry
meats were markedly increasing. However, the limited use of antibiotics as treatments
and as growth promoters became a serious problem due to the emergence of antibiotic
resistance and microbial challenges in commercial poultry farming causing significant
economic losses. Therefore, exploring other alternatives such as using feed additives
like β-glucans were widely studied and used to meet the demands of the consumers.
Β-glucans can be found in yeast, fungi, some bacteria, and cereals such as oats, barley, and
corn. This review focused on the different functions and effects of β-glucans in poultry.
Β-glucans were known to have immunomodulation effects by upregulating the cytokines
and other immune cells to overcome a disease. Aside from its immunomodulation
effects, it can also increase the intestinal villi and crypts. Furthermore, an increase
in growth performance was also observed. This evidence is promising but further
research is required to properly establish the various functions of β-glucans in p
... Utility of postbiotic enzymatically treated non-GMO Saccharomyces cerevisiae is among the dietary strategies that has been proposed to be beneficial in transitioning piglets upon weaning (Kiarie et al., 2011). Yeast β-glucans and mannan oligosaccharides are functional and are responsible for the immunomodulating properties and prevention of pathogenetic bacteria (e.g., Escherichia coli) binding and proliferating on intestinal surfaces (Anwar et al., 2017). The mode of action differs from ZnO which improves growth performance by increasing feed intake and, therefore, alleviating the negative effects typically associated with the post-weaning growth lag (i.e., high intestinal pH, thinner mucosal layer, reduced expression of tight junction proteins; Pluske, 2016). ...
... As mentioned, yeast supplementation has improved growth of pigs following an immune challenge, which is a result of β-glucans in the yeast. β-glucans found in yeast increase circulating immunoglobulins, particularly secretory IgA (Anwar et al., 2017). The yeast product used in this study contained 40% cell wall materials including β-1,3/1,6 glucans and mannan oligosaccharides. ...
... Although lactic acid accounts for the greater proportion of ileal digesta SCFA (Kiarie et al., 2007), butyric acid is more important for gut health. Butyric acid accounts for most of the energy that is utilized by intestinal epithelial cells, has immunoregulatory effects, and increases mucin production (Anwar et al., 2017); therefore, from our results, pigs provided diets with ZnO had an improved gastrointestinal environment and an improved innate immune system. ...
Growth performance and physiological responses of nursery piglets when fed enzymatically treated yeast (HY40) and pharmacological ZnO alone or in combination, were investigated. A total of 144 pigs (21d old, BW 7.32±0.55 kg) were placed in 36 pens (4 pigs/pen). Pigs were randomly assigned to one of four dietary treatments (n=9): [1] control corn-wheat-soybean meal diet (control), [2] control + HY40 (HY40), [3] control +ZnO and [4] control + HY40 + ZnO (HY40+ZnO). Inclusion of HY40 and ZnO was 0.5% and 3,000 ppm in phase I (d 0 to 14), respectively, and halved in phase II (d 15 to 42). All diets contained 0.2% TiO2 for determination of apparent total tract digestibility (ATTD) of components. Body weight and feed disappearance was recorded weekly. One pig per pen was sacrificed for organ weights, blood, and tissue samples on d 14. Except for phase II, when HY40+ZnO pigs had greater average daily feed intake (P=0.004) than all other treatments, there were no (P>0.05) interactions between HY40 and ZnO on growth performance. Pigs fed HY40 or ZnO containing diets were heavier (P<0.05) than pigs fed without by the end of the study. On d 14, pigs fed additives exhibited higher (P≤0.009) ATTD of dry matter (DM) and gross energy (GE) than control pigs. On d 28, pigs fed control, HY40 and HY40+ZnO had greater (P≤0.022) ATTD of DM, crude protein, and GE than piglets fed ZnO only. Pigs fed HY40+ZnO had lower ileal digesta E. coli concentration (P<0.05) than HY40 and control pigs. Ileal digesta of pigs fed ZnO diets had higher lactobacillus to E. coli ratio (1.44 vs. 1.20; P=0.001), exhibited higher concentrations of acetic (P=0.01) and butyric acid (P=0.01) but lower lactic (P=0.02) and total short chain fatty acids (P=0.033) than pigs fed non-ZnO diets. Greater (P<0.05) mRNA expression of nutrient transporters, tight junction proteins and fecal excretion of zinc (Zn) was observed in ZnO pigs relative to non-ZnO pigs. Pigs fed HY40 diets had greater (P=0.002) villus height to crypt depth ratio (VH:CD) than non-HY40 pigs. The concentration of plasma IgA was higher (P=0.04) in HY40+ZnO pigs relative to other pigs whereas HY40 pigs showed higher (P<0.001) jejunal IgA than non-HY40 pigs. Although the mode of action of HY40 and ZnO differed, the present study indicated that HY40 improved growth performance and jejunal function and immunity, making HY40 an effective alternative to pharmacological ZnO for nursery pigs.
... Yeast is a feed additive that provides both nutrients and bioactive compounds (i.e., β-glucans and mannan oligosaccharides; Anwar et al., 2017) and can be provided in various forms (i.e., probiotic, prebiotic, postbiotic, or combinations thereof) depending on processing methods (as reviewed by Patterson et al., 2023). Since yeast is an immune-modulating additive, it has been shown to reduce growth in nursery pigs when included in high quantities, likely due to overstimulation of the immune system (Li et al., 2006;Anwar et al., 2017). ...
... Yeast is a feed additive that provides both nutrients and bioactive compounds (i.e., β-glucans and mannan oligosaccharides; Anwar et al., 2017) and can be provided in various forms (i.e., probiotic, prebiotic, postbiotic, or combinations thereof) depending on processing methods (as reviewed by Patterson et al., 2023). Since yeast is an immune-modulating additive, it has been shown to reduce growth in nursery pigs when included in high quantities, likely due to overstimulation of the immune system (Li et al., 2006;Anwar et al., 2017). Yeast-dependent stimulation of the immune system could, however, promote increased antibody production in reproductive animals and subsequent passive immune transfer to the offspring via colostrum (Hasan et al., 2018). ...
Fifty gilts (initial body weight [BW] 190.7 ± 4.2 kg) were recruited on day 85 of gestation and were used until day 19 of lactation to assess the dose–response of inactivated yeast via hydrolyzation (HY) inclusion on offspring growth and immunoglobulin (Ig) transfer prior to weaning. Gilts were assigned to one of the 5 experimental diets: a control with no HY (HY0) or inclusion of 0.25% (HY0.25), 0.5% (HY0.5), 1.0% (HY1.0), or 1.2% (HY1.2) HY. Gilts were weighed on days 85 and 110 of gestation and days 1 and 19 (weaning) after farrowing. Offspring were weighed on days 1 and 19 of age. On lactation day 1 (approximately 24 h after farrowing), colostrum, gilt plasma, and plasma from 2 median BW piglets were collected and on day 19, plasma from each gilt and 2 median BW piglets per litter were collected for determination of Ig concentrations. Contrast statements were used to assess the linear, quadratic, cubic, and quartic effects of HY inclusion. The inclusion of HY had minimal effects on gilt BW or litter characteristics at birth (total number born and born alive, piglet birth weight). Lactation average daily feed intake of the gilts tended to increase then decrease with increasing HY inclusion (quadratic; P = 0.085). Piglet preweaning average daily gain (linear, quadratic, and quartic; P < 0.05) and BW at weaning (quadratic and quartic; P < 0.05) increased then decreased with increasing HY inclusion. On lactation day 1, colostrum and gilt plasma Ig concentrations were not affected by dietary treatment (P > 0.10) but piglet IgA and IgM decreased then increased with HY inclusion level (cubic; P < 0.05). On lactation day 19, piglet plasma IgG tended to increase with HY inclusion (linear; P = 0.099). In summary, increasing HY inclusion in late gestating and lactating gilt diets improved immune transfer in the first 24 h after birth and piglet preweaning growth rates and BW at weaning. Therefore, maternal feeding of HY could be used as a strategy to improve offspring immunocompetence and BW at weaning, with possible carryover benefits for the postweaning phase.
... Another effective natural antimicrobial compound is β-glucan, which is a soluble fibre found in the cell walls of bacteria, fungi, yeasts, and certain plants. They have been commonly used in the industry as an alternative to antibiotics due to the development of antibiotic resistance [83]. Studies show that β-glucan can stimulate phagocytosis and suppress pathogen invasion of Salmonella spp. in the gut intestine, while maintaining the integrity of the mucous protective layers for the expulsion of enteric pathogen invasion [83]. ...
... They have been commonly used in the industry as an alternative to antibiotics due to the development of antibiotic resistance [83]. Studies show that β-glucan can stimulate phagocytosis and suppress pathogen invasion of Salmonella spp. in the gut intestine, while maintaining the integrity of the mucous protective layers for the expulsion of enteric pathogen invasion [83]. It can also be applied to soybean fermentation, where production of β-glucan can reduce the growth of pathogenic microorganisms. ...
Fermented soybean products have played a significant role in Asian diets for a long time. Due to their diverse flavours, nutritional benefits, and potential health-promoting properties, they have gained a huge popularity globally in recent years. Traditionally, soybean fermentation is conducted spontaneously, using microorganisms naturally present in the environment, or inoculating with traditional starter cultures. However, many potential health risks are associated with consumption of these traditionally fermented soybean products due to the presence of food pathogens, high levels of biogenic amines and mycotoxins. The use of starter culture technology in fermentation has been well-studied in recent years and confers significant advantages over traditional fermentation methods due to strict control of the microorganisms inoculated. This review provides a comprehensive review of microbial safety and health risks associated with consumption of traditional fermented soybean products, and how adopting starter culture technology can help mitigate these risks to ensure the safety of these products.
... Bacterial infections are important diseases in humans and animals that can be treated using antibacterial drugs; however, increasing global awareness of the side effects of chemical-based drugs resulted in an attitude to use natural ingredients to prevent such diseases and utilization of immune stimulants to boost the immune system of the body against these infections has been increased. Administration of BG can be helpful in enhancing the clearance of bacteria, advanced bactericidal activity, more cytokine production modulation, and increasing neutrophils and monocytes number, which all lead to an antibiotic activity (Anwar et al. 2017). It should be noted that the immunomodulation function of BG can be upregulated by both parenteral and oral applications (Daou and Zhang 2012). ...
... Enhanced sIgA secretion and goblet cells number might also lead to the integrity of the mucous protective layers and expel invasive pathogens (Brandtzaeg 2010). Direct killing or biding mechanism of BG against pathogens was not reported yet (Anwar et al. 2017). Schwartz and Vetvicka (2021 reviewed the application of BGas (an alternative to antibiotics) in poultry against the most frequently intestinal infections such as those from E. coli, Salmonella typhimurium, and Clostridium perfringens. ...
Gut microbiota (GMB) in humans plays a crucial role in health and diseases. Diet can regulate the composition and function of GMB which are associated with different human diseases. Dietary fibers can induce different health benefits through stimulation of beneficial GMB. β-glucans (BGs) as dietary fibers have gained much interest due to their various functional properties. They can have therapeutic roles on gut health based on modulation of GMB, intestinal fermentation, production of different metabolites, and so on. There is an increasing interest in food industries in commercial application of BG as a bioactive substance into food formulations. The aim of this review is considering the metabolizing of BGs by GMB, effects of BGs on the variation of GMB population, influence of BGs on the gut infections, prebiotic effects of BGs in the gut, in vivo and in vitro fermentation of BGs and effects of processing on BG fermentability.
... The need to decrease the use of antibiotics in livestock and poultry production has given the livestock industry a boost. (Anwar, et al., 2017;Cheng, et al., 2019) [6,7] . However, the inclusion of dietary herbs and their extracts has growth-promoting roles in poultry (Movahhedkhah et al., 2019) [12] . ...
... The need to decrease the use of antibiotics in livestock and poultry production has given the livestock industry a boost. (Anwar, et al., 2017;Cheng, et al., 2019) [6,7] . However, the inclusion of dietary herbs and their extracts has growth-promoting roles in poultry (Movahhedkhah et al., 2019) [12] . ...
The use of antibiotics in poultry feed at therapeutic or subtherapeutic levels as well as bacterial resistance to antibiotics, which impedes human health, are causing growing public concern. To ensure animal health, productivity, and carcass quality, livestock farmers must be given alternatives to antibiotic growth promoters. The main objective of this study is to evaluate the effect of supplementation of plant source growth promoters (Garlic, Ginger, Neem and Moringa leaves meal) and their combinations, as Natural Growth Promoters in broiler chickens. A total of 360-day-old Cobb-500 broiler chickens were purchased from Olam hatchery, Chukum. The chicks were fed commercial diets for seven (7) days. Thereafter, the birds were randomly allotted to six (6) dietary treatments with four (4) replicates each, 15 birds per replicate. The rations were labeled as Diets: T1=basal diet + Antibiotics, T2=basal diet + Garlic, T3=basal diet + Ginger, T4=basal diet + Neem leaf meal, T5=basal diet + Moringa leaf meal and T6=basal diet + mixture of natural growth-promoter herbs. The data was analyzed by One-way analysis of variance (ANOVA) using R-studio application software, LSD was used to compare significant difference among the treatments means at P < 0.05. The results revealed that there were no significant (P > 0.05) differences among the dietary treatment means for daily feed intake, weight gain, and feed conversion ratio in all the three phases (starter, finisher, and overall). the results for carcass and organs characteristics revealed that there were no significant difference (P>0.05) among the treatment means for live weight, plucked weight, evisceration weight, carcass weight, head weight, shank weight, neck weight, thigh weight, breast weight, wing weight, dressing percentage. While a significant difference (P < 0.05) was shown on the leg weight and drumstick weight where diets T3 and T2 were the highest. The weight of viscera organs; revealed a very high significant (P < 0.001) difference in kidney weight, and a high significance (P < 0.01) difference in spleen weight, Proventriculus weight, and small intestine weight, with a significant (P < 0.05) difference in lung weight. The results suggested that the natural herbal growth promoters are similar and had better output compared with commercial antibiotics growth promoters in most of the body cut parts. Therefore, these Natural Plant Growth Promoters will be used to replace Antibiotics Growth promoters without any adverse effects on broiler performance.
... The yeast parietal adsorption activity is different from yeast to yeast, depending on the structural characteristics and chemical composition of the outermost layer of the cell wall. This layer is made up of mannoproteins, which represent 25-50% of the entire cell wall [40]. Parietal mannoproteins relate to an inner matrix of amorphous β-1,3 glucan and are partly released in wine ( Figure 2). ...
... Constitution of yeast and yeast cell wall. Yeast β-glucans form long chains of a β-(1→3) linked glucan backbone with β-(1→6) linked glucose side branches Adapted from Anwar et al.[40]. ...
A relevant trend in winemaking is to reduce the use of chemical compounds in both the vineyard and winery. In organic productions, synthetic chemical fertilizers, pesticides, and genetically modified organisms must be avoided, aiming to achieve the production of a “safer wine”. Safety represents a big threat all over the world, being one of the most important goals to be achieved in both Western society and developing countries. An occurrence in wine safety results in the recovery of a broad variety of harmful compounds for human health such as amines, carbamate, and mycotoxins. The perceived increase in sensory complexity and superiority of successful uninoculated wine fermentations, as well as a thrust from consumers looking for a more “natural” or “organic” wine, produced with fewer additives, and perceived health attributes has led to more investigations into the use of non-Saccharomyces yeasts in winemaking, namely in organic wines. However, the use of copper and sulfur-based molecules as an alternative to chemical pesticides, in organic vineyards, seems to affect the composition of grape microbiota; high copper residues can be present in grape must and wine. This review aims to provide an overview of organic wine safety, when using indigenous and/or non-Saccharomyces yeasts to perform fermentation, with a special focus on some metabolites of microbial origin, namely, ochratoxin A (OTA) and other mycotoxins, biogenic amines (BAs), and ethyl carbamate (EC). These health hazards present an increased awareness of the effects on health and well-being by wine consumers, who also enjoy wines where terroir is perceived and is a characteristic of a given geographical area. In this regard, vineyard yeast biota, namely non-Saccharomyces wine-yeasts, can strongly contribute to the uniqueness of the wines derived from each specific region.
... Recent studies reported that, for organic acids [5,6], beta-glucans + MOS, when used in the diet of weaning pigs, are potentially beneficial to growth performance on days 1-21, bacterial population balance in feces and diarrhea incidence reduction [14]. Another study showed that the consumption of beta-glucans could attenuate intestinal damage in weaned pigs upon enterotoxigenic Escherichia coli challenge, related to the suppressed secretion of inflammatory cytokines and enhanced serum immunoglobulins, as well as improved intestinal epithelium functions and microbiota [15,16]. Piglets in the AO+YW-1 group (organic acids and prebiotic) had a smaller number of animals to be medicated, medication only for diarrhea, in the higher dose of the additive (AO+YW-2). ...
The piglet nursery phase is one of the critical moments in production, especially in the first few weeks after weaning. Growth-promoting antibiotics have always been used in this phase, but the world is banning or limiting the use of antibiotics for this purpose, which has led researchers to seek alternatives, with an emphasis on organic and natural ones. As a result, this study aimed to evaluate whether a combination of organic acids and their derivatives (ammonium formate, formic acid, ammonium propionate, and acetic acid) and yeast wall (mannan oligosaccharides and beta-glucans) in piglet feeding during the nursery phase has positive effects on the SCFA profile in feces and animal health reflected in greater weight gain. A 40-day experiment was conducted in a completely randomized design containing three treatments, each with nine replicates and three piglets per replicate: negative control (NC: without additives), and a combination of organic acids and yeast wall at doses of 1 and 2 kg/ton (AO+YW-1 and AO+YW-2, respectively). Animals received four diets: pre-starter 1 (d1–7), pre-starter 2 (d8–14), starter 1 (d15–25), and starter 2 (d26–40). The animals were weighed on the day of the diet change. Blood and feces were collected on days 14 and 40 of the experiment. Piglets from the AO+YW-1 group showed more significant weight gain than NC. Feed intake was higher in piglets from the AO+YW-1 group considering the first 25 days of the experiment compared to NC; there was no treatment effect on feed conversion. Piglets from NC had higher levels of C-reactive protein and ferritin, while AO+YW-2 had higher levels of interleukin 10 and lower levels of TNF-α. A greater quantity of SCFA was observed in the feces of piglets on d40, related to the changes in propionic, butyric, isovaleric, and valeric acids. Therefore, the combination of organic acids and yeast wall used at a dose of 1 kg/ton proved to be an additive option for the diet of piglets in the nursery phase to enhance weight gain and reduce the number of doses of injectable antibiotics.
... Yeast and its derivatives (live yeast, yeast extracts and yeast cell wall components) contain numerous bioactive compounds (Kim et al. 2022). Among them, β-glucan, a yeast cell wall component, consists of the polymerisation of glucose through β-1,3/1,6 glycosidic linkages and is widely studied in poultry, based on its beneficial effect on innate and acquired immunity (Shao et al. 2013;Anwar et al. 2017;Ezzat et al. 2024). ...
This study was conducted to examine the effect of dietary natural compounds, such as β‐glucan, carotenoids, oligosaccharides and anthocyanins, on immune response and tight junction proteins in broiler chickens. A total of 900 one‐day‐old chickens were allocated to five treatments in three floor pens (replicates) of 60 broilers per pen. Chickens were fed five diets: a control (basal) diet, a diet supplemented with β‐glucan at 0.05%, or diets supplemented with carotenoids, oligosaccharides or anthocyanins at 0.5% of each compound. Male broilers were randomly selected for sample collections. On Day 25, plasma samples were collected from the brachial vein. On Day 26, six broilers were intraperitoneally injected with 2 mg of lipopolysaccharide per kg of body weight. Twelve hours later (Day 27), blood and ileum samples were collected to determine immune parameters and tight junction proteins using ELISA assays. The results showed that anthocyanin supplementation reduced the level of interleukin‐1β compared to the lipopolysaccharide‐injected control group (p = 0.047), which suggests that anthocyanin could partly alleviate the inflammation. Carotenoids reached a lower level of interleukin‐6 compared to the β‐glucan treatment (p = 0.0466). β‐Glucan (p = 0.0382) and oligosaccharides (p = 0.0449) increased the level of plasma immunoglobulin G compared to the challenged control group, which may indicate an enhanced humoral immunity. Furthermore, β‐glucan (except for occludin 2), carotenoids, oligosaccharides and anthocyanins increased (p < 0.05) the levels of ileal zonula occludens‐1, occludin 1 and occludin 2 compared to the lipopolysaccharide‐challenged control chickens. This may suggest that all the bioactive substances improved the gut barrier function. The plasma levels of tight junction proteins show higher concentrations in lipopolysaccharide‐challenged groups compared to the non‐challenged groups (p < 0.05). This may refer to the tight junction disruption and appearance in circulation as a reflection of lipopolysaccharide exposure.
... Previous studies have demonstrated the antimicrobial and anti-tumour properties of natural herbal products by stimulating lymphocyte proliferation and eliminating pathogens [53]. In the context of coccidiosis, certain bioactive foods and probiotics have been recognised for their ability to confer protection against Eimeria infection by activating specific cellular and humoral immune responses [54,55]. ...
Avian diseases, especially coccidiosis, represent a significant threat to poultry production, demanding research into the use of herbal supplements in birds’ diets. So, the aim of this study was to assess the efficacy of selected herbal components in mitigating coccidiosis in broilers and to examine their overall impact on the productivity traits of broilers. A 35-day feeding trial was conducted with 1200 male ROSS 308 broiler chickens in two poultry facilities, one non-infected, using either usual coccidiostats (UC⁻) or 500 g/t herbal additive (consisting of Holarrhena antidysenterica, Ficus religiosa, Berberis aristata, Allium sativum, Embelia ribes, and Azadirachta indica; HA⁻) and the other intentionally exposed to Eimeria via drinking water at 7 days old, with corresponding control and experimental groups (UC⁺ and HA⁺). Dietary interventions significantly influenced broiler chicken body weight (BW) and average daily gain (ADG) throughout the trial, notably on day 21, with UC⁺ treatment yielding the highest values. Herbal supplements did not affect the feed conversion ratio (FCR) or liveability. Under infection, litter dry matter (DM) content differences were notable on days 14 and 21, favouring herbal additive treatments (HA⁻ and HA⁺). Herbal supplements also impacted Eimeria presence in the duodenum and jejunum on day 21, with notable differences between treatments. Despite several limitations, the study reveals that herbal additions may effectively manage Eimeria infection and enhance litter quality in broiler production, since control treatments demonstrated improved development and anatomy.
... Similarly, dietary supplementation with yeast b-glucans has been demonstrated to promote growth performance (Tian et al., 2016) and enhance gut health in chickens (Anwar et al., 2017). In addition, b-glucans inclusion has been shown to stimulate humoral and cell-mediated immune responses (Omara et al., 2021;Wang et al., 2021), alleviated aflatoxin B (1)-induced DNA damage in lymphocytes (Zimmermann et al., 2015), and prevented C. perfringens-induced necrotic enteritis (Tian et al., 2016), thereby used as an alternative to antibiotics (Schwartz and Vetvicka, 2021). ...
... Yeast nucleotides are often used in livestock and poultry diets to replace antibiotics and as valuable feed additives either in the form of yeast extracts or as pure constituents [8,9]. Nucleotides are essentially supplemented in poultry diets because the animal's ability for synthesis is insufficient in some conditions, such as fast development, stress, and illness [10]. ...
Stress in poultry production is energy-demanding. Nucleotides and yeast cell-wall products are essential nutrients for broiler performance, gut function, and immune response. Antibiotics, like florfenicol, negatively affect the immune system. A total of 600 one-d-old broiler chickens(Cobb-500) were weighed and randomly allotted into four groups with three replicates each. The control group (G1) received the basal diet, G2 received a diet supplemented with a combination of nucleotides and Saccharomyces cerevisiae derivatives (250 g/Ton), G3 received the basal diet and medicated with florfenicol (25 mg/Kg body weight) in drinking water for 5 days, while G4 received a combination of nucleotides and Saccharomyces cerevisiae-derivatives (250 g/Ton) and medicated with florfenicol in drinking water. Growth performance criteria were recorded weekly. Blood, intestinal contents, small-intestine sections, and litter samples were collected to measure birds’ performance, carcass yields, leukocytic counts, antioxidant capacity, antibody titres, phagocytic index, caecal Clostridia, intestinal histomorphometry, and litter hygiene. Nucleotide-supplemented groups (G2 and G4) revealed significant (p ≤ 0.05) improvements in feed conversion, and body weight, but not for carcass yields in comparison to the control. Dietary nucleotides in G2 elevated blood total proteins, leucocytic count, antioxidant capacity, and phagocytic index, while they lowered blood lipids and litter moisture and nitrogen (p ≤ 0.05). Dietary nucleotides in G4 ameliorated the immunosuppressive effect of florfenicol (p ≤ 0.05) indicated in reducing caecal Clostridia, improving duodenal and ileal villi length, and increasing blood albumin and globulin levels, and phagocytosis%. Supplementing diets with nucleotides and yeast products has improved the immune system and provided a healthier gut for broilers.
... Direct interaction between the cellulose-coated emulsion particles and the yeast cell is observed in Figs. 1 and 2. This adhesion seems to occur by formation of fibrils connecting the yeast cell wall with the cellulose shell of the emulsion particles (Fig. 2d). The external shell of the cellulose-coated emulsion particles contains cellulose hydrogel while the yeast cell wall includes polysaccharides β-glucans and chitin among other components [36][37][38][39] . The adhesion between the emulsion particles and yeast cell, as shown in Figs. 1 and 2, may be explained by direct interaction between the cellulose hydrogel and the components of the yeast cell wall. ...
In the quest for alternative renewable energy sources, a new self-assembled hybrid configuration of cellulose-coated oil-in-water emulsion particles with yeast was formed. In this research, the addition of yeasts (S. cerevisiae) to the micro-particle emulsion revealed a novel self-assembly configuration in which the yeast cell is connected to surrounding cellulose-coated micro-particles. This hybrid configuration may enhance the simultaneous saccharification and fermentation process by substrate channeling. Glucose produced by hydrolysis of the cellulose shells coating the micro-particles, catalyzed by cellulytic enzymes attached to their coating, is directly fermented to ethanol by the yeasts to which the particles are connected. The results indicate ethanol yield of 62%, based on the cellulose content of the emulsion, achieved by the yeast/micro-particle hybrids. The functionality of this hybrid configuration is expected to serve as a micro-reactor for a cascade of biochemical reactions in a “one-pot” consolidated process transforming cellulose to valuable chemicals, such as biodiesel.
... Beyond using antibiotics as growth enhancer, these have few drawbacks including residual effects, drug toxicity and rise in bacterial resistance [24,23,18,33]. Such ills have guided the European Union to prohibit antibiotics use like growth promoters [8]. Therefore, awareness to natural plus safe choices such as herbs alternate to antibiotics is increasing day by day [15,42]. ...
Aspire of the present study was to scrutinize the effects of Moringaoleiferaleaf extract (MOLE) on various growth biomarkers (feed intake,final live weight,weight gain and feed conversion ratio)of broiler chicks.A 6 weeks trials study was done on Day old broiler chicks (Hubbard) with 350 in number distributed into 5 equal groups. Group 1 st were named as Control group was fed on basal feed common to other groups and water without MOLE.The othertreatment groups MOLE2, MOLE4, MOLE6 andMOLE8 were provided with the basal feed with2, 4, 6 and 8mL ofMoringaoleiferaleaf extract per liter of their drinking water respectively.It was observed through the results that the broilers chicks provided with4% MOLEin watershowed significant (P<0.05) highestfinal and net body weight in comparison to control and other treatment groups. A significant (P<0.05) increased trend in live and dressed body weight was observed as compared to control group. As compared to control group, significant increased values of Hemoglobin and Packed cell volume were observed in broiler chicks fed on 2, 4,6, 8% of MOLE. Same trend was observed for white blood cells. However it was observed through the experiment that chicken of control group had lower counts of RBC and WBC, PCV and lymphocyte levels. It was concluded in the study that adding of 4% MOLE in drinking water caused an increase in growth performance and carcass traits. The broiler fed on feed with 4% Moringa showed highest performance compared to others .
... also demonstrated that pigs fed the diet containing pharmacological ZnO had greater alpha diversity and less relative abundance of E. coli in favor of bacteria from the genus Lactobacillus in the cecal mucosal microbiome. da Silva et al. (2021) reported ZnO increased bacteria abundance in the genus Roseburia, which is generally considered beneficial as it produces butyrate, a beneficial short-chain fatty acid (Anwar et al., 2017). Conversely, in the current study, the inclusion of BSFLM did not modulate the cecal mucosal microbiota to the same extent. ...
At weaning, one hundred pigs (21 d of age; 6.96 ± 0.23 kg BW) were used to determine the effect of partially replacing soybean meal (SBM) in corn- and SBM-based nursery diets on growth performance, fecal scores, Escherichia coli (E. coli) colony forming units (CFU), and cecal mucosal microbial profile when weaned into non-disinfected nursery pens. Pens were randomly assigned to one of four dietary treatments (n = 5): high-complexity (contained highly digestible animal proteins and 10.8% SBM) with and without 3,000 ppm ZnO (HC + and HC−, respectively; representative of commercial diets), low-complexity (corn- and SBM-based; 31.8% SBM; LC), or LC with 30% inclusion of full-fat black soldier fly larvae meal (BSFLM) to partially replace SBM (LCFL; 8.0% SBM). Diets were fed for 14 d (phase I), followed by 4 wk of a common corn-SBM diet (phase II). Fecal E. coli CFU and cecal mucosal microbial 16s rRNA community profiles were assessed 7 d after weaning. During phase I, pigs fed LC and LCFL had lower average daily gains (P < 0.05) than pigs fed HC + and HC−, which were not different. Average daily feed intake was not different for pigs fed LC and LCFL, but lower than for pigs fed HC− (P < 0.001); pigs fed HC + had greater feed intake in phase I vs. all other treatment groups (P < 0.001). Upon nursery exit, only pigs fed LCFL had lower BW than pigs fed HC− (P < 0.05), with intermediate values observed for HC + and LC. Day 3 fecal scores were greater for pigs fed LCFL vs. HC + (P < 0.05) and day 7 E. coli CFU were greater for all treatment groups vs. HC + (P < 0.001). Pigs fed HC− (P < 0.01), LC (P < 0.05), and LCFL (P < 0.05) had lower alpha diversity for cecal mucosal microbiota compared to HC+. At the genus level, pigs fed LC had lower Lactobacillus relative abundance vs. pigs fed HC + (P < 0.01). Therefore, BSFLM can partially replace SBM without sacrificing growth performance vs. nursery pigs fed corn- and SBM-based diets, but both groups had reduced phase I growth performance vs. pigs fed highly digestible diets containing animal proteins when weaned into non-disinfected pens. The BSFLM did not influence fecal E. coli CFU or improve fecal consistency after weaning and therefore, is less effective at minimizing digestive upsets vs. HC + diets.
... Similarly, in ovo or dietary supplementation of perbiotics (polysaccharides) including yeast beta-glucans enhanced gut health in chickens (Anwar et al., 2017), alleviated aflatoxin B (1)-induced DNA damage in lymphocytes (Zimmermann et al., 2015), and prevented C. perfringens-induced necrotic enteritis (Tian et al., 2016). Likewise, supplementation of mannan-oligosaccharides (MOS) in broilers increased Lactobacillus community diversity and decreased C. perfringens and E. coli in the ileum (Kim et al., 2011). ...
Early embryonic exogenous feeding of bioactive substances is a topic of interest in poultry production, potentially improving gastrointestinal tract (GIT) development, stimulating immunization, and maximizing the protection capability of newly hatched chicks. However, the biophysiological actions and effects of in ovo administered bioactive substances are inconsistent or not fully understood. Thus, this paper summarizes the functional effects of bioactive substances and their interaction merits to augment GIT development, the immune system, and microbial homeostasis in newly hatched chicks. Prebiotics, probiotics, and synbiotics are potential bioactive substances that have been administered in embryonic eggs. Their biological effects are enhanced by a variety of mechanisms, including the production of antimicrobial peptides and antibiotic responses, regulation of T lymphocyte numbers and immune-related genes in either up- or downregulation fashion, and enhancement of macrophage phagocytic capacity. These actions occur directly through the interaction with immune cell receptors, stimulation of endocytosis, and phagocytosis. The underlying mechanisms of bioactive substance activity are multifaceted, enhancing GIT development, and improving both the innate and adaptive immune systems. Thus summarizing these modes of action of prebiotics, probiotics and synbiotics can result in more informed decisions and also provides baseline for further research.
... Horst et al. (2019) stated that dietary b-glucan can improve the host immunological response to Newcastle vaccinations. Furthermore, b-glucan extracted from yeast increases the number of cells releasing immunoglobulin A (IgA) and could, therefore, substitute for antibiotics in the treatment of certain enteric pathogens in poultry (Anwar et al., 2017). S. cerevisiae can also increase the phosphorus and crude protein and decrease the fiber content in the feed. ...
Poultry production has been developing in Vietnam with challenges of disease. Thus, feed additive should be investigated not only growth but also health enhancement. Here, we aimed to determine the effects of Saccharomyces cerevisiae-fermented rice (FR) and β-glucan on turkey's growth performance, carcass characteristics, immune and fatty acid (FA) profiles. A total of 180 turkey chicks aged 1-56 days were randomly assigned to five sextuplicate groups and the birds had ad libitum feed and water access throughout the experiment. The five treatment groups were given the same diet with different proportions of FR and β-glucan. Broilers supplemented with 4% β-glucan and 4% FR presented the highest and second-highest growth performance, respectively. The 4% β-glucan and 4% FR treatments resulted in the highest carcass characteristic values without significantly affecting the breast or thigh meat pH or cooking loss. The 4% β-glucan and 4% FR treatments maximally increased the Newcastle disease (ND) antibody titers at 28, 42 and 56 days, respectively as well as thymus organ index. The foregoing treatments did not significantly affect the blood profiles relative to the control. However, the 4% FR treatment lowered the blood cholesterol levels (p > 0.05). The total FA profiles did not significantly differ among treatments. Nevertheless, both the β-glucan and FR treatments increased the MUFA levels compared to that of the control (p > 0.05). Hence, the dietary administration of 4% β-glucan and FR to turkey broilers could effectively improve their growth performance and immunity.
... Main theories on yeast cell wall interactions with mycotoxins (adapted from Luo et al.42 and Anwar et al.240 ) ...
Fungi-induced postharvest diseases are the leading causes of food loss and waste. In this context, fruit decay can be directly attributed to phytopathogenic and/or mycotoxin-producing fungi. The U.N. Sustainable Development Goals aim to end hunger by 2030 by improving food security, sustainable agriculture, and food production systems. Antagonistic yeasts are one of the methods presented to achieve these goals. Unlike physical and chemical methods, harnessing antagonistic yeasts as a biological method controls the decay caused by fungi and adsorbs and/or degrades mycotoxins sustainably. Therefore, antagonistic yeasts and their antifungal mechanisms have gained importance. Additionally, mycotoxins' biodetoxification is carried out due to the occurrence of mycotoxin-producing fungal species in fruits. Combinations with processes and agents have been investigated to increase antagonistic yeasts' efficiency. Therefore, this review provides a comprehensive summary of studies on preventing phytopathogenic and mycotoxigenic fungi and their mycotoxins in fruits, as well as biocontrolling and biodetoxification mechanisms.
... Glucan is as important a component of YG as MOS. Our results are consistent with previous studies that reported that glucan and MOS attenuated barrier dysfunction and enhanced gut health in broiler chickens (41). Nevertheless, the possible mechanism by which yeast products regulate the intestinal physical barrier is unknown. ...
The active ingredients extracted from yeast are important for regulating animal health. The aim of the current research was to explore the impacts of dietary yeast glycoprotein (YG) on the growth performance, intestinal morphology, antioxidant capacity, immunity and disease resistance of largemouth bass (Micropterus salmoides). A total of 375 juvenile fish (6.00 ± 0.03 g) were allocated into 15 fiberglass tanks. Triplicate tanks were assigned to each diet. The dietary YG inclusion was as follows: the first group was given a high fishmeal diet (40% fishmeal, 0% YG) (FM) and the second group was given a low fishmeal diet (30% fishmeal and 15% soybean meal, 0% YG) (LFM). The fish in the third, fourth and fifth groups were fed the LFM diet supplemented with 0.5% (LFM+YG0.5), 1.0% (LFM+YG1.0) and 2.0% (LFM+YG2.0) YG, respectively. After a 60- day feeding trial, a challenge test using A. hydrophila was carried out. The results showed that the final body weight (FBW) and weight gain rate (WGR) in the LFM+YG2.0 group were significantly higher than those in the LFM group and were no significantly different from those in the FM group. This may be partially related to the activation of the target of rapamycin (TOR) signaling pathway. Dietary YG supplementation enhanced intestinal physical barriers by upregulating the intestinal tight junction protein related genes (claudin1, occludin and zo2) and improving the structural integrity of the gut, which may be partially associated with AMPK signaling pathway. Moreover, dietary YG increased the antioxidant capacity in the gut, upregulated intestinal anti-inflammatory factors (il-10, il1-1β and tgf-β) and downregulated proinflammatory factors (il-1β and il-8), which may be partially related to the Nrf2/Keap1 signaling pathways. The results of the challenge test indicated that dietary supplementation with 0.5 or 1.0% YG can increase the disease tolerance of largemouth bass against A. hydrophila. In conclusion, the present results indicated that dietary supplementation with YG promotes the growth performance, intestinal immunity, physical barriers and antioxidant capacity of largemouth bass. In addition, 1.0% of dietary YG is recommended for largemouth bass based on the present results.
... Architecture de la paroi de S. cerevisiae[4]. ...
All living organisms, including walled cells, exhibit key characteristics such as differentiation, growth, and reproduction. An understanding of these features in normal and/or pathological contexts is inextricably linked to the cell-wall ; an elastic sturdy structure which constitutes the outermost boundary of the cell. The cell-wall affords mechanical protection, dictates cell shape, and provides a counter force against the inner turgor pressure. This thesis deals specifically with Saccharomyces
cerevisiae yeast which constitutes a well-established model system to decipher fundamental processes relevant to eukaryotic cells.
The first part of this thesis addresses the cell-wall mechanical properties. To this end, a viscoelasticmodel has been developed within the finite strain range due to the soft nature of the yeasts. Such cells were considered to be thin walled, liquid-filled, axisymmetric structures. To describe the delayed response of the cell, a hyperelastic behavior was coupled with a creep-like potential where the evolution equation of the strain-like internal variables is in accordance with the continuum thermodynamics requirements.
The inner fluid of the cell is taken to be incompressible and is represented by a normal pressure load on the inner surface of the cell-wall. Follower loads are used at this stage, the amplitudes of which are implicitly accounted for by the use of the constant inner volume constraint. Using a combined theoretical, numerical and experimental approach, the viscoelastic cell-wall parameters have been
identified.
Different mechanical properties of the cell-wall have been found by the use, on the one hand, of the atomic force microscopy and, on the other hand, of a micromanipulation-like technique. The necessityof a cell-wall representation by at least two sets of layers with sensitively different mechanical properties has been established. Numerical simulations have been conducted concomitantly in solid
and shell approaches to highlight the efficiency of the proposed framework.
The second part of this thesis focuses on the growth of budding yeast powered by the turgor pressure. A theoretical model has been developed in a solid approach to describe the emergence of the bud and its evolution over time. From the purely mechanical point of view, to control bud formation, two essential parameters have been involved in the evolution equation : a characteristic time, and a stress-like threshold. Afterwards, the model has been extended to the shell approach. Later on, the modelling framework has been improved by simulating the contractile ring formed at the base of the protrusion region as a natural growth phenomenon. The whole framework has been qualitatively evaluated by the use of a finite element modeling.
... The addition of GLC to feed enhanced gut health and disease resistance in birds challenged with necrotic enteritis by stimulating the gene expression of antimicrobial peptides [13]. By enhancing the populations of cells secreting IgA and goblet cells, yeastbased GLC can serve as growth inducers and prospective antibiotic alternatives against specific microorganisms in birds [14]. Moreover, macrophages obtained from chickens fed a diet supplemented with GLC showed upregulated expression of IL-1 [15], IL-2, interferon (IFN)-γ [16], IL-4, and IL-18 [17]. ...
Recently, researchers have been intensively looking for novel, safe antibiotic alternatives
because of the prevalence of many clinical and subclinical diseases affecting bird flocks and the risks
of using antibiotics in subtherapeutic doses as feed additives. The present study intended to evaluate
the potential use of 1,3-β-glucans (GLC) as antibiotic alternative growth promotors and assessed the
effect of their dietary inclusion on the growth performance, carcass traits, chemical composition of
breast muscles, economic efficiency, blood biochemical parameters, liver histopathology, antioxidant
activity, and the proinflammatory response of broiler chickens. This study used 200 three-day-
old ROSS broiler chickens (50 chicks/group, 10 chicks/replicate, with an average body weight of
98.71 ± 0.17 g/chick). They were assigned to four experimental groups with four dietary levels of
GLC, namely 0, 50, 100, and 150 mg kg−1
, for a 35-day feeding period. Birds fed diets containing
GLC showed an identical different growth rate to the control group. However, the total feed intake
(TFI) increased quadratically in the GLC50 and GLC100 groups as compared to that in the control
group. GLC addition had no significant effect on the weights of internal and immune organs, except
for a decrease in bursal weight in the GLC150 group (p = 0.01). Dietary GLC addition increased
the feed cost and total cost at 50 and 100 mg kg−1 doses. The percentages of n-3 and n-6 PUFA
in the breast muscle of broiler chickens fed GLC-supplemented diets increased linearly in a dose-
dependent manner (p < 0.01). The serum alanine aminotransferase (ALT) level and the uric acid level
were quadratically increased in the GLC150 group. The serum levels of total antioxidant capacity,
catalase, superoxide dismutase, interleukin-1β, and interferon-gamma linearly increased, while the
MDA level decreased in the GLC-fed groups in a dose-dependent manner. Normal histological
characterization of different liver structures in the different groups with moderate round cells was
noted as a natural immune response around the hepatic portal area. The different experimental
groups showed an average percentage of positive immunostaining to the proinflammatory marker
transforming growth factor-beta with an increase in the dose of GLC addition. The results suggest
that GLC up to 100 mg kg−1
concentration can be used as a feed additive in the diets of broiler
chickens and shows no adverse effects on their growth, dressing percentage, and internal organs.GLC addition in diets improves the antioxidant activity and immune response in birds. GLC help
enrich the breast muscle with n-3 and n-6 polyunsaturated fatty acids.
... El papel de los antibióticos entéricos [165]. Los probióticos o Direc-fed Microbials (DFM), como se encuentran en la literatura, son una parte de microorganismos vivos, enzimas libres, minerales traza y coadyuvantes en un portador comestible, esta especie es muy útil cuando el animal sufre altos grados de estrés, lo cual afecta la salud, por ejemplo, cuando el ave es sometida a cambios de clima bruscos podría bajar la calidad de la carne de forma significativa [166], los probióticos presentan beneficios en el tracto intestinal del ave al restringir la colonización [28], [167], [168]. ...
Tema y alcance: Las implicaciones de factores externos dentro de la seguridad alimentaria crea afectaciones que ponen en riesgo la inocuidad de los alimentos cárnicos avícolas, la investigación de las principales bacterias como Salmonella sp, Campylobacter sp y E. coli son de suma importancia, debido a que aportan para la mitigación de estos microorganismos durante la cadena de producción. Características: Se realizó una revisión literaria de artículos científicos, con el interés de recopilar información pertinente a los productos avícolas, agentes externos, brotes relacionados por consumo de pollo y estrategias actuales más comunes que reducen infecciones a la población. Hallazgos: un crecimiento en el consumo de carne de ave, donde surge la necesidad de garantizar un control de posibles puntos de infección en las diferentes partes de fabricación del cárnico avícola, para esto último se evidencia de la efectividad del uso de los antibióticos, prebióticos y probióticos como mecanismos de saneamientos del alimento. Conclusión: a pesar de los avances en la investigación de los patógenos y mejoramientos del proceso en las diferentes etapas de producción aún persisten infecciones referentes al consumo de carne de pollo.
... Beta-glucans derived from yeast cell walls bind to the TLR2 and CLR family and dectin-1 receptor on enterocytes and immune cells [96,97]. Activated receptors give rise to Ig secretion and increase the number of goblet cells for the maintenance of intestinal structural integrity [98]. Li et al. (2006) [99] demonstrated that pigs fed β-glucans can inhibit secretion of TNF-α and IL-6 due to increased IL-10; therefore, nutrients would be utilized for increased growth performance rather than for immune responses. ...
Simple Summary
The use of microorganisms has become a trend as nutritional and functional feedstuffs become widely used in swine and poultry diets. Microorganisms, as coproducts obtained from the food industry and biorefineries, can reduce not only the burdens of the natural ecosystem but also the high costs of feedstuffs. It is possible to mitigate food and land competition with humans in the current global issues. These microorganisms could be promising and sustainable alternatives in animal diets because they contain highly valuable proteins, amino acids, fatty acid composition, and biogenic metabolites, which are beneficial for animal production. Microorganisms could be good alternatives to replace plant and animal-based protein supplements with high protein and a balanced amino acid composition. Lipid-rich microalgae and yeasts could be alternative energy feeds with valuable fatty acids used to enhance intestinal health and meat quality. In addition, microorganisms could be functional feed additives due to their cell contents and their cell wall bioactive components. However, there still are some limitations to using microorganisms, including the sources and dose of those microorganisms, which may cause negative effects on growth and health. Thus, this research focused on investigating the use of nutritional and functional microorganisms as feedstuffs and feed additives to replace conventional feedstuffs for enhancing the growth and intestinal health of nursery pigs and broilers.
Abstract
The objectives of this review paper are to introduce the structures and composition of various microorganisms, to show some applications of single cells as alternative protein supplements or energy feeds in swine and poultry diets, and to discuss the functional effects of microorganisms as feed additives on the growth performance and intestinal health of nursery pigs and broilers. Microorganisms, including bacteria, yeasts, and microalgae, have been commonly supplemented in animal diets because they are cost-effective, stable, and have quantitative production that provides nutritional and functional benefits to pigs and broilers. Microorganisms could be alternative antibiotics to enhance intestinal health due to bioactive components from cell wall components, which interact with receptors on epithelial and immune cells. In addition, bioactive components could be digested by intestinal microbiota to produce short-chain fatty acids and enhance energy utilization. Otherwise, microorganisms such as single-cell protein (SCP) and single-cell oils (SCOs) are sustainable and economic choices to replace conventional protein supplements and energy feeds. Supplementing microorganisms as feedstuffs and feed additives improved the average daily gain by 1.83%, the daily feed intake by 0.24%, and the feed efficiency by 1.46% in pigs and broilers. Based on the properties of each microorganism, traditional protein supplements, energy feeds, and functional feed additives could be replaced by microorganisms, which have shown benefits to animal’s growth and health. Therefore, specific microorganisms could be promising alternatives as nutritional and functional feedstuffs in animal diets.
... The prohibition of the use of antibiotics in poultry production in several countries around the world has led nutritionists nowadays to seek foods, mostly plants, which, in addition to having good nutritional profiles, also promote growth effects in birds (Anwar et al., 2017;Ulger et al., 2017;Cheng et al., 2019;Ekizoğlu et al., 2020). Several plants known for their beneficial effects on human nutrition have been researched as alternative ingredients in animal feeding. ...
This study evaluated the effects of including Moringa oleifera (moringa) leaf meal on performance, carcass yield and characteristics, and relative organ weights of broilers from 10 to 42 days of age. We distributed 420 male Cobb 500 chicks in a completely randomized design with five treatments and six replicates with 14 birds each. Treatments consisted of five experimental diets in which the moringa leaf meal was included at 0, 1.5, 3.0, 4.5, and 6.0% in the diets. The following performance variables were evaluated: weight gain, feed intake, and feed conversion; weights and yields of carcass, carcass traits, organs, and abdominal fat; and feet color. Significant differences between the treatment means were analyzed by Dunnett’s test. The meal inclusion levels did not affect performance, carcass characteristics and yield, or organs weight. However, feet pigmentation increased linearly, and abdominal fat was greater only at the 1.5% level when compared with the control group. Moringa leaf meal can be included in the diet of broilers from 10 to 42 days of age, up to the level of 6%, without compromising performance or carcass yield of these birds.
broiler; carcass traits; carotenoids; performance
... Similarly, dietary supplementation with yeast b-glucans has been demonstrated to promote growth performance (Tian et al., 2016) and enhance gut health in chickens (Anwar et al., 2017). In addition, b-glucans inclusion has been shown to stimulate humoral and cell-mediated immune responses (Omara et al., 2021;Wang et al., 2021), alleviated aflatoxin B (1)-induced DNA damage in lymphocytes (Zimmermann et al., 2015), and prevented C. perfringens-induced necrotic enteritis (Tian et al., 2016), thereby used as an alternative to antibiotics (Schwartz and Vetvicka, 2021). ...
This study aimed to analyze the growth performance, antioxidant activity, serum lipid profile, meat quality, and lipid metabolism of broiler chickens fed mixtures containing Enteromorpha polysaccharide (EP) and yeast glycoprotein (YG). A total of 400-one-day-old broiler chickens were randomly divided into four treatment groups of 10 replicates with 10 birds each replicate. The dietary treatments consisted of the control group (fed basal diet), and diets supplemented with Enteromorpha polysaccharide (EP; 400mg/kg), yeast glycoprotein (YG;400mg/kg), and EP+YG (200mg/kg EP + 200mg/kg YG). Compared with the control group, EP+YG supplementation enhanced growth performance and significantly reduced (P<0.05) serum total triglyceride (TG), cholesterol (CHOL), and low-density lipoprotein LDL levels, and increased high-density lipoprotein (HDL) levels. Besides, birds fed EP+YG supplemented diet exhibited higher (P<0.05) serum catalase (CAT), total antioxidant capacity, superoxide dismutase (SOD), and lower malonaldehyde (MDA) activities, and upregulated expressions of related genes, such as nuclear factor-erythroid factor 2-related factor 2 (NRF2), SOD1, and glutathione peroxidase 4 (GPX4) in the liver and intestinal tissues than the control group. Interestingly, higher (P<0.05) serum SOD and lower MDA contents were observed in the EP+YG group than in either EP or YG group, suggesting a synergetic effect. Breast meat from EP+YG supplemented group had significantly higher redness value (a*), and lower pH24, total saturated fatty acid profiles, C14:0, C16:0, C18:0 fatty acid, atherogenic index, and thrombogenicity index than meat from the control group (P<0.05). Furthermore, the mRNA expressions of fatty acid synthesis genes were downregulated (P<0.05), whereas lipid β-oxidation-related genes were upregulated (P<0.05) in the liver of the EP+YG supplemented group than in the control group. Overall, our data suggest that dietary EP+YG inclusion may have a synergistic effect, and therefore improve growth performance, regulate serum biochemical indexes, enhance antioxidant activity, and modulate lipid metabolism in broilers, indicating that it is a potential feed additive for chickens.
... Moreover, one of the most important characteristics of yeast β-D-glucans is their ability to adsorb several mycotoxins [37][38][39], and, thus, their inclusion in animal feed may lead to the suppression of these compounds' hazardous effects. Among the numerous beneficial effects associated with β-glucan administration, the most significant results have been found with β-glucan obtained from the yeast Saccharomyces cerevisiae [40]. Due to their reported properties, β-glucans may provide a new method for reducing antibiotic use in chicken diets [35]. ...
Simple Summary
Yeast and yeast-derived products are largely employed in animal nutrition to support animals’ health and to improve their performance. Thanks to their components, including mannans, β-glucans, nucleotides, vitamins, and other compounds, yeasts have numerous beneficial effects. Among yeast-derived products, hydrolyzed yeasts and yeast cultures have received less attention, but, although the results are somewhat conflicting, in most of the cases, the available literature shows improved performance and health in poultry. Thus, the aim of this review is to provide an overview of hydrolyzed-yeast and yeast-culture employment in poultry nutrition, exploring their effects on the production performance, immune response, oxidative status, gut health, and nutrient digestibility. A brief description of the main yeast bioactive compounds is also provided.
Abstract
Yeasts are single-cell eukaryotic microorganisms that are largely employed in animal nutrition for their beneficial effects, which are owed to their cellular components and bioactive compounds, among which are mannans, β-glucans, nucleotides, mannan oligosaccharides, and others. While the employment of live yeast cells as probiotics in poultry nutrition has already been largely reviewed, less information is available on yeast-derived products, such as hydrolyzed yeast (HY) and yeast culture (YC). The aim of this review is to provide the reader with an overview of the available body of literature on HY and YC and their effects on poultry. A brief description of the main components of the yeast cell that is considered to be responsible for the beneficial effects on animals’ health is also provided. HY and YC appear to have beneficial effects on the poultry growth and production performance, as well as on the immune response and gut health. Most of the beneficial effects of HY and YC have been attributed to their ability to modulate the gut microbiota, stimulating the growth of beneficial bacteria and reducing pathogen colonization. However, there are still many areas to be investigated to better understand and disentangle the effects and mechanisms of action of HY and YC.
... Due to the immunomodulating aspects of β-glucans, in addition to their ability to improve the gut microbiome and promote gastro-intestinal health, some studies suggest the use of β-glucans as feed ingredients in animal husbandry. There is evidence that they are capable of enhancing the natural immunity of animals, promoting productivity and decreasing the need for antibiotics [234][235][236]. The inclusion of yeast cell β-glucans in poultry diets was shown to increase the intestinal clearance of pathogens by protecting intestinal barriers, stimulating phagocytosis and suppressing pathogen invasion [237][238][239][240]. Supplementation of piglet diets with Sacharomyces cerevisiae β-1,3-glucans increased production performances and resulted in significant stimulation of phagocytosis by both peripheral blood monocytes and neutrophils, and improved responses to endotoxin challenge [241]. ...
β-glucans are a diverse group of polysaccharides composed of β-1,3 or β-(1,3-1,4) linked glucose monomers. They are mainly synthesized by fungi, plants, seaweed and bacteria, where they carry out structural, protective and energy storage roles. Because of their unique physicochemical properties, they have important applications in several industrial, biomedical and biotechnological processes. β-glucans are also major bioactive molecules with marked immunomodulatory and metabolic properties. As such, they have been the focus of many studies attesting to their ability to, among other roles, fight cancer, reduce the risk of cardiovascular diseases and control diabetes. The physicochemical and functional profiles of β-glucans are deeply influenced by their molecular structure. This structure governs β-glucan interaction with multiple β-glucan binding proteins, triggering myriad biological responses. It is then imperative to understand the structural properties of β-glucans to fully reveal their biological roles and potential applications. The deconstruction of β-glucans is a result of β-glucanase activity. In addition to being invaluable tools for the study of β-glucans, these enzymes have applications in numerous biotechnological and industrial processes, both alone and in conjunction with their natural substrates. Here, we review potential applications for β-glucans and β-glucanases, and explore how their functionalities are dictated by their structure.
... The cell wall plays an important role in adsorption [12], Which made of Mannoprotein which represents 40% of cell wall mass, While, β1-3 glucan represent 50%, about 10% β1-6 glucan and 1-3% chitin [14], as explained in Figure 1. [15,16,17,18]. ...
Biosorption ability of commercial dried Saccharomyces cerevisiae (Baker’s yeast), to remove the Methyl green dye from water, was studied. This dye was chosen due to wide using of it in the different industries which is dumped into wastewater. With a view to explore the optimum conditions for adsorption of dye, Batch experiments were performed under various experimental affecting conditions, which are dye concentration, temperature, contact time. The experiment's batches were held using various initial concentrations of dye from 10 to 50 mg L-1, absorbent (Baker's yeast) dosage 0.075g at diverse temperatures (20, 30 and 40°C), and pH=7. In which the results have shown when the temperature increased the adsorption efficiency increased too. The removal percentage (%R) of dye by the baker’s yeast reached equilibrium after 80 minutes. As well as, adsorption isotherm models (Freundlich and Langmuir) were studied. The maximum biosorption capacity values were calculated at mentioned conditions. Furthermore, Kinetic and Thermodynamic parameters were calculated for this adsorption process, which are indicating the process is endothermic, spontaneous process in nature and follow pseudo 2. Order model.
... The cell wall plays an important role in adsorption [12], Which made of Mannoprotein which represents 40% of cell wall mass, While, β1-3 glucan represent 50%, about 10% β1-6 glucan and 1-3% chitin [14], as explained in Figure 1. [15,16,17,18]. ...
KEYWORDS Methyl green dye; Biosorption; Baker's yeast; Adsorption Isotherm Models; Thermodynamic parameters ABSTRACT: Biosorption ability of commercial dried Saccharomyces cerevisiae (Baker's yeast), to remove the Methyl green dye from water, was studied. This dye was chosen due to wide using of it in the different industries which is dumped into wastewater. With a view to explore the optimum conditions for adsorption of dye, Batch experiments were performed under various experimental affecting conditions, which are dye concentration, temperature, contact time. The experiment's batches were held using various initial concentrations of dye from 10 to 50 mg L-1 , absorbent (Baker's yeast) dosage 0.075g at diverse temperatures (20, 30 and 40°C), and pH=7. In which the results have shown when the temperature increased the adsorption efficiency increased too. The removal percentage (%R) of dye by the baker's yeast reached equilibrium after 80 minutes. As well as, adsorption isotherm models (Freundlich and Langmuir) were studied. The maximum biosorption capacity values were calculated at mentioned conditions. Furthermore, Kinetic and Thermodynamic parameters were calculated for this adsorption process, which are indicating the process is endothermic, spontaneous process in nature and follow pseudo 2. Order model.
... Autolyzed yeast (AY) is the product of cellular degradation and solubilization by its own enzymes (Schiavone et al., 2014) that contains approximately 55%-64% β-glucans, 35%-40% MOS, 13% protein, 9% lipids, and 2% chitin (Anwar et al., 2017;Liu et al., 2018). ...
The 63 commercial pigs were divided into three groups consisting of seven replicates of three piglets each. The experimental diets were (1) control diet, (2) diet with autolyzed yeast (AY) 0.5%, and (3) diet with AY 1.0%. Compared to the control group, using AY 0.5% in the diet reduced average daily feed intake (ADFI) and improved feed conversion ratio (FCR) (p < 0.05). The blood urea nitrogen (BUN) and neutrophil/lymphocyte ratio (N/L) in blood decreased with the addition of AY 0.5% (p < 0.05). The pH at 6‐h postmortem of meat in the 0.5% AY diet group was higher than for the control group (p < 0.05). Backfat thickness (p = 0.09) and P2‐backfat thickness (p = 0.07) tended to decrease, while the fat free index (FFI; p = 0.07) tended to increase with 0.5% AY supplementation. The protein percentage (p = 0.07) and the a* value (redness) (p = 0.08) in the meat tended to increase, and the springiness increased with 0.5% AY supplementation (p < 0.05). An appropriate level of AY supplementation can impact positively on the physiological functions in swine with a consequent seems to improve in qualitative traits of the meat quality.
... Anwar et al., 2017. A review of β-glucans as a growth promoter and antibiotic alternative against enteric pathogens in poultry. ...
The evaluation of functional feed additives in commercial conditions with the pacific whiteleg shrimp (L. Vannamei).
... Com o crescente aumento da população mundial, tem-se incrementado também a demanda por proteína animal segura e de qualidade. A proibição do uso de antibióticos na produção animal, em vários países do mundo, tornou-se um desafio para os nutricionistas da atualidade, levando-os a buscarem alimentos, em sua maioria vegetais, que apresentem compostos com características promotoras de crescimento (Anwar et al., 2017;Cheng et al., 2019). ...
A maior parte dos ingredientes destinados a alimentação de animais não ruminantes se constituem de origem vegetal e podem conter, em sua composição, níveis variáveis de polissacarídeos não amiláceos (PNAs). Estes são conhecidos por comprometerem, a depender dos níveis de inclusão do ingrediente, concentrações e tipos nos alimentos, o desempenho e a saúde intestinal de suínos e aves. As carboidrases são enzimas que degradam carboidratos e tem sido utilizada como alternativas para melhorias no aproveitamento de fontes alimentares que contenham grandes quantidades de PNAs, com resultados positivos sobre aproveitamento energético da dieta e diminuindo os efeitos negativos desses compostos. Celulases, xilanases, betaglucases, amilases, galactosidades, dentre outras tem sido suplementadas nas rações desses animais e têm mostrado serem afetivas em melhorar as características morfométricas, estado imunológico e microbiano do intestino, com impactos positivos sobre a saúde intestinal e desempenho. Logo, estre trabalho teve por objetivo revisar os efeitos da utilização e enzimas carboidrases na dieta de aves e seus efeitos sobre a saúde intestinal.
... Lymphocytes are the common precursor cells for both the adaptive immune system as well as for natural killer cells, involved in defending the host against virus infections. β-glucans derived from the yeast Saccharomyces cerevisiae have been demonstrated to exert the most significant positive effect [35]. An increasing body of evidence demonstrates health benefits of βglucans in poultry [36]. ...
The occurrence of microbial challenges in commercial poultry farming causes significant economic losses. Antibiotics have been used to control diseases involving bacterial infection in poultry. As the incidence of antibiotic resistance turns out to be a serious problem, there is increased pressure on producers to reduce antibiotic use. With the reduced availability of antibiotics, poultry producers are looking for feed additives to stimulate the immune system of the chicken to resist microbial infection. Some β-glucans have been shown to improve gut health, to increase the flow of new immunocytes, increase macrophage function, stimulate phagocytosis, affect intestinal morphology, enhance goblet cell number and mucin-2 production, induce the increased expression of intestinal tight-junctions, and function as effective anti-inflammatory immunomodulators in poultry. As a result, β-glucans may provide a new tool for producers trying to reduce or eliminate the use of antibiotics in fowl diets. The specific activity of each β-glucan subtype still needs to be investigated. Upon knowledge, optimal β-glucan mixtures may be implemented in order to obtain optimal growth performance, exert anti-inflammatory and immunomodulatory activity, and optimized intestinal morphology and histology responses in poultry. This review provides an extensive overview of the current use of β glucans as additives and putative use as antibiotic alternative in poultry.
... Yeast-based β-glucans may be used as growth promoters and potential antibiotic alternatives in poultry against certain enteric pathogens by increasing populations of cells expressing secretory IgA, as well as goblet cells [24]. They can also modulate expression profiles of cytokines during a coccidiosis infection via enhanced innate and T helper Type I (Th1)-mediated immune response [4]. ...
Simple Summary
Avian coccidiosis is the leading parasitic disease in the poultry industry and means to control its damages continue to be explored. This study evaluated the feeding effects of a yeast-derived β-glucan on expression of immune response genes in the spleen, thymus, and bursa of commercial broiler chickens during an Eimeria challenge. The study consisted of two dietary treatments (0% or 0.1% β-glucan) each with or without a coccidiosis challenge. There were significant effects from dietary β-glucan, Eimeria challenge, and their interaction for several gene targets in the spleen, thymus, and bursa on days 10 and 14 of age. Based on the current results, supplementation of dietary β-glucan in Eimeria-challenged birds enhanced and modulated the expression of immune response genes during coccidiosis.
Abstract
This study investigated the effects of a yeast-derived β-glucan (Auxoferm YGT) supplementation on mRNA expression of immune response genes in the spleen, thymus, and bursa of broiler chickens during a mixed Eimeria infection. Day (d)-old chicks (n = 1440) were fed diets containing 0% or 0.1% YGT. On d 8 post-hatch, half the replicate pens (n = 8) were challenged with a mixed inoculum of E. acervulina, E. maxima, and E. tenella. On d 10 and d 14 post-hatch, the spleen, thymus, and bursa were collected to evaluate mRNA abundance by quantitative real-time PCR. Data were analyzed using PROC GLIMMIX model (2-way interaction) and differences were established by LS-MEANS with significance reported at p ≤ 0.05. In spleen tissues at d 10, expression of interleukin (IL)-10 and inducible nitric oxide synthase (iNOS) were elevated in both 0.1% YGT-fed challenged and non-challenged birds. In thymus tissues at d 14, expression of IL-10, IL-17F, interferon (IFN)-γ, iNOS, and macrophage migration inhibitory factor (MIF) were elevated in challenged birds fed 0.1% YGT. In bursal tissues at d 10 and d 14, expression of IL-10, IFN-γ, iNOS (d 10 only), and MIF were elevated in 0.1% YGT-fed challenged and non-challenged birds. Dietary β-glucan supplementation to chicken diets modulated their immune response to the Eimeria challenge.
... It is constituted of polysaccharides, proteins and lipids. The proportion of the components of the cell wall can vary according to the culture and harvest conditions of the yeast [26] and, specially, to the yeast strain [27], but it is around 35e40% mannoproteins, 50e55% b-1,3-glucans, 5e10% b-1,6-glucans and 2% chitin [28]. The mechanical strength of the wall is mainly due to the innermost layer of the wall, consisting mainly of b-1,3-glucans and chitin. ...
Due to the improvements in detection sensitivity, inductively coupled plasma-mass spectrometry (ICP-MS) has matured to be an exceptional tool for the elemental analysis of small objects. The characterisation of individual metallic nanoparticles by so-called single particle ICP-MS (SP-ICP-MS) has paved the way for the analysis of smallest biological systems like individual cells. Developments in single cell ICP-MS (SC-ICP-MS) have increased significantly with essential efforts in the introduction of cell suspensions into the ionisation source by developing nebulizer/spray chamber systems that allow maximum transport efficiencies. These developments have been accompanied with the commercial launches of ICP-MS instruments for better control of spectral interferences and time-of-flight instruments with improved sensitivity.
In this review, special emphasis was put on summarizing the recent developments in sample introduction systems for liquid cell suspensions. Where available, analytical figures of merit will be compared for the different approaches as well as the most relevant applications of SC-ICP-MS.
... β-glucans are composed by polymerization of glucose through 1,3/1,6 β-glycoside linkages [109]. In addition to their occurring in the yeast cell wall, we can find β-glucans in other sources having different structures. ...
Although the immunomodulatory properties of prebiotics were demonstrated many years ago in poultry, not all mechanisms of action are yet clear. Dendritic cells (DCs) are the main antigen-presenting cells orchestrating the immune response in the chicken gastrointestinal tract, and they are the first line of defense in the immune response. Despite the crucial role of DCs in prebiotic immunomodulatory properties, information is lacking about interaction between prebiotics and DCs in an avian model. Mannan-oligosaccharides, β-glucans, fructooligosaccharides, and chitosan-oligosaccharides are the main groups of prebiotics having immunomodulatory properties. Because pathogen-associated molecular patterns on these prebiotics are recognized by many receptors of DCs, prebiotics can mimic activation of DCs by pathogens. Short-chain fatty acids are products of prebiotic fermentation by microbiota, and their anti-inflammatory properties have also been demonstrated in DCs. This review summarizes current knowledge about avian DCs in the gastrointestinal tract, and for the first-time, their role in the immunomodulatory properties of prebiotics within an avian model.
Prokaryotes are known to produce and secrete a broad range of biopolymers with a high functional and structural heterogeneity, often with critical duties in the bacterial physiology and ecology. Among these, exopolysaccharides (EPS) play relevant roles in the interaction of bacteria with eukaryotic hosts. EPS can help to colonize the host and assist in bacterial survival, making this interaction more robust by facilitating the formation of structured biofilms. In addition, they are often key molecules in the specific recognition mechanisms involved in both beneficial and pathogenic bacteria-host interactions. A novel EPS known as MLG (Mixed-Linkage β-Glucan) was recently discovered in rhizobia, where it participates in bacterial aggregation and biofilm formation and is required for efficient attachment to the roots of their legume host plants. MLG is the first and, so far, the only reported linear Mixed-Linkage β-glucan in bacteria, containing a perfect alternation of β (1 → 3) and β (1 → 4) bonds. A phylogenetic study of MLG biosynthetic genes suggests that far from being exclusive of rhizobia, different soil and plant-associated bacteria likely produce MLG, adding this novel polymer to the plethora of surface polysaccharides that help bacteria thrive in the changing environment and to establish successful interactions with their hosts.
In this work, a quantification method for MLG is proposed. It relays on the hydrolysis of MLG by a specific enzyme (lichenase), and the subsequent quantification of the released disaccharide (laminaribiose) by the phenol-sulfuric acid method. The protocol has been set up and optimized for its use in 96-well plates, which makes it suitable for high-throughput screening (HTS) approaches. This method stands out by its fast processing, technical simplicity, and capability to handle multiple samples and biological replicates at a time.
This investigation was designed to determine the effect of Saccharomyces cerevisiae (S. cerevisiae) supplementation on production variables, carcass characteristics, internal organ weights, gut linear measurements, digesta pH values, haematology and serum biochemical indices of Boschveld chickens. The biochemical composition, mineral and amino acid profiles of S. cerevisiae were analysed. A total of six hundred (n = 600) day-old, unsexed, healthy Boschveld chicks were distributed randomly to six (n = 6) dietary treatments. Each group (treatment) consisted of five (n = 5) replicates of 20 chicks each in a complete randomised design. The feeding programme consisted of commercial broiler starter (1 to 49 days) and grower (50 to 91 days) mash feeds. During each feeding phase, dietary treatments had the same caloric density and the same protein level, but with different levels of S. cerevisiae – as follows: Y0 (0.0), Y1 (2.5), Y2 (5.0), Y3 (7.5), Y4 (10.0) and Y5 (12.5) g kg-1 feed. A quadratic function was deployed to estimate the ideal levels of S. cerevisiae for optimal response of different variables. A linear function was used to establish the relationship between response variables and dietary S. cerevisiae. Pearson's correlation coefficient (r) was used to establish the association among production variables.
Proximate results revealed that S. cerevisiae had high crude protein (49.6 %) content, moderate carbohydrate (36.15%) and low crude fibre (2.90 %) content. The mineral analysis showed that phosphorus (1.20) and potassium (0.85) g 100g-1 were the highest minerals in S. cerevisiae. Glutamic acid and aspartic acid were the main amino acids in S. cerevisiae and accounted for 52.33 % of the total dispensable amino acids. Results also showed that S. cerevisiae is dominated by hydrophilic and acidic amino acids. Dietary probiotic S. cerevisiae did not influence (p>0.05) feed intake (FI) and metabolisable energy (ME), but boosted (p<0.05) average daily gain (ADG), feed conversion ratio (FCR), live weight (LW) and nitrogen retention (NR) of Boschveld chickens. Dietary probiotic S. cerevisiae influenced (p<0.05) some carcass characteristics, internal organ weights, linear measurements and digesta pH values of the gastrointestinal tract of Boschveld chickens. Dietary probiotic S. cerevisiae had a significant effect (p<0.05) on packed cell volume (PCV), haemoglobin (Hb), mean corpuscular haemoglobin (MCH), total protein, cholesterol and triglyceride. However, it did not influence (p>0.05) red blood cells (RBCs) count, mean corpuscular volume (MCV), mean corpuscular Hb concentration (MCHC), platelets, white blood cells (WBCs) count, heterophils, lymphocytes, monocytes, albumen, glucose and uric acid. Strong positive relationships were observed between S. cerevisiae levels and PCV, Hb and MCV values. Production variables, carcass and internal organ parameters were optimised at different S. cerevisiae supplementation levels. The S. cerevisiae supplementation level for optimal productivity decreased as Boschveld chickens grew older. Based on the results reported here, S. cerevisiae inclusion in the diet of Boschveld chickens had no adverse effects and can be used as a natural growth promoter.
Highly prolific modern hens are susceptible to metabolic disorders that could be modulated by functional feedstuffs such as enzymatically treated yeast (ETY). Therefore, we assessed the dose-response of ETY on hen-day egg production (HDEP), egg quality attributes, organ weight, bone ash, and plasma metabolites in laying hens. A total of 160 thirty-week-old Lohmann LSL lite hens were placed in 40 enriched cages (4 birds/cage) based on body weight (BW) and allocated to 5 diets in a completely randomized design for a 12-wk trial. The diets were isocaloric and isonitrogenous corn and soybean meal based supplemented with 0.0, 0.025, 0.05, 0.1, or 0.2% ETY. Feed and water were provided ad libitum; HDEP and feed intake (FI) were monitored weekly, whereas egg components, eggshell breaking strength (ESBS), and thickness (EST) were monitored biweekly, and albumen IgA concentration was measured on wk 12. At the end of the trial, 2 birds/cage were bled for plasma and necropsied for liver, spleen, and bursa weight, ceca digesta for short chain fatty acids (SCFA) and tibia and femur for ash content. Supplemental ETY reduced HDEP quadratically (P = 0.03); the HDEP was 98, 98, 96, 95, and 94% for 0.0, 0.025, 0.05, 0.1, and 0.2% ETY, respectively. However, ETY linearly and quadratically (P = 0.01) increased egg weight (EW) and egg mass (EM). Specifically, EM was 57.9, 60.9, 59.9, 58.9, and 59.2 g/b for 0.0, 0.025, 0.05, 0.1, and 0.2% ETY, respectively. Egg albumen increased linearly (P = 0.01), and egg yolk decreased linearly (P = 0.03) in response to ETY. In response to ETY, the ESBS and plasma Ca increased linearly and quadratically (P ≤ 0.03). Plasma concentration of total protein and albumin increased quadratically (P ≤ 0.05) with ETY. Diets had no (P > 0.05) effects on FI, FCR, bone ash, SCFA, and IgA. In conclusion, 0.1% or higher ETY reduced egg production rate; however, linear improvement in EW and shell quality linked to larger albumen and higher plasma protein and Ca suggested modulation in protein and calcium metabolism.
The intestinal microbiome is responsible for the fermentation of complex carbohydrates and orchestrates the immune system through gut microbiota-derived metabolites. In our previous study, we reported that supplementation of Enteromorpha polysaccharide (EP) and yeast glycoprotein (YG) in combination synergistically improved antioxidant activities, serum lipid profile, and fatty acid metabolism in chicken. However, the mechanism of action of these polysaccharides remains elusive. The present study used an integrated 16S-rRNA sequencing technology and untargeted metabolomics technique to reveal the mechanism of action of EP+YG supplementation in broiler chickens fed basal diet or diets supplemented with EP+YG (200mg/kg EP + 200mg/kg YG). The results showed that EP+YG supplementation altered the overall structure of caecal microbiota as evidenced by β diversities analysis. Besides, EP+YG supplementation changed the microbiota composition by altering the community profile at the phylum and genus levels. Furthermore, Spearman correlation analysis indicated a significant correlation between altered microbiota genera vs serum cytokine levels and microbiota genera vs volatile fatty acids production. Predicted functional analysis showed that EP+YG supplementation significantly enriched amino acid metabolism, nucleotide metabolism, glycan biosynthesis and metabolism, energy metabolism, and carbohydrate metabolism. Metabolomics analysis confirmed that EP+YG supplementation modulates a myriad of caecal metabolites by increasing some metabolites, including pyruvic acid, pyridoxine, spermidine, spermine, and dopamine, and decreasing metabolites related to lipid metabolisms such as malonic acid, oleic acid, and docosahexaenoic acid. The quantitative enrichment analysis results further showed that glycolysis/gluconeogenesis, citric acid cycle, tyrosine metabolism, glycine, serine, and threonine metabolism, and cysteine and methionine metabolism were the most important enriched pathways identified with enrichment ratio >11, whereas, fatty acid biosynthesis and biosynthesis of unsaturated fatty acids pathways were suppressed. Together, the 16S-rRNA and untargeted metabolomics results uncovered that EP+YG supplementation modulates intestinal microbiota and their metabolites, thereby influencing the important metabolism pathways, suggesting a potential feed additive.
A relevant trend in winemaking is to reduce the use of chemical compounds in both the vineyard and winery. In organic productions, synthetic chemical fertilizers and pesticides must be avoided, aiming to achieve the production of a “safer wine”. Also, in line with consumer preferences and due to the effects of global climate change, new trends have emerged in wine fermentation and wine technology, namely new genetic engineering methods, such as CRISPR/Cas9, described as efficient, versatile, cheap, easy-to-use, and able to target multiple sites.
Consumers are also looking for wines with less ethanol and fruitier aromas, but with a good balance in terms of acidity and mouthfeel. An appropriate acidity, pleasant to the palate is more difficult to achieve in wines that have high acidity. Non-conventional yeasts, in the past considered spoilage yeasts, now can be used to enhance the aroma profile of wine or to modulate wine composition, namely wine acidity, reinforcing the role of non-Saccharomyces as selected strains for controlling fermentations mostly in co-fermentation with Saccharomyces cerevisiae.
Moringa oleifera (MO) is a widely used as the nutritious and non-traditional feed supplementation containing kinds of bioactive substances. However, the enhancement effect of Moringa oleifera leaf Polysaccharide (MOLP) as a feed additive in broilers growth performance and immunity remains unclear. In this study, MOLP was obtained by water extraction and alcohol precipitation method, then purified with Trichloroacetic acid (TCA) assay. Chickens were randomly divided into 4 groups, to receive different doses of MOLP (0, 0.1, 0.2, 0.4g/kg) in feed for 3 weeks. The body weight gain (BWG) and feed consumption were recorded for feed conversion ratio (FCR) and average daily feed intake (ADFI) calculation. Broiler chickens were sacrificed and sampled on day 14, 21, 28 (D 14, D 21, and D 28) respectively. Serological indicators, including total protein (TP), albumin (ALB), globulin (GLO), and creatinine (CREA) were detected. ELISA kits were applied for detecting the levels of immunoglobulin A (IgA), immunoglobulin G (IgG), interleukin-2 (IL-2), and tumor necrosis factor (TNF-α). From D 21 to D 28, the results showed that middle dose of MOLP significantly increased BWG and ADFI as well as liver and bursa indexes when compared with the control group. In addition, TP and GLO were also increased ( P <0.05). All MOLP treatments enhanced the serum concentrations of IgG and IL-2 ( P <0.01). Furthermore, results of quantitative RT-PCR showed that high dose of MOLP treatment significantly increased ( P <0.001) the mRNA expression levels of IL-2 and TNF-α of chickens relative to the control group. In conclusion, the results showed that MOLP supplementation contributed to improve growth performance and immune response in broiler chickens, and MOLP could be considered as a promising feed additive.
The understanding of the synbiotics´ impact on the host is incomplete. To improve the knowledge we study the effect of Lacto-Immuno-Vital synbiotic preparation in chickens on local and systemic immune response by evaluation of immunocompetent cells in the peripheral blood and jejunal mucosa. Haematological method was used for determination of white blood cell count, and flow cytometry for measurement the functions of phagocytes and subpopulation of lymphocytes (CD3, CD4, CD8, IgM, and IgA). Cell Qest programme (Germany) was used for analysing of data obtained from flow cytometer and GraphPad Prism version 4.0 for comparison by paired t-test between control and experimental groups. The experiment was conducted in a commercial broiler chicken fattening farm, the birds were handled and sacrificed in a humane manner. A flock of 64,400 one-day-old Hybrid ROSS 308 chickens were included in the 42-day experiment. The chickens were randomly divided into two equal groups, experimental and control, and each group of chickens was housed in a different hall while maintaining the same conditions. The chickens in the experimental group (Lactovital) received 500 g of Lacto-Immuno-Vital® (Hajduvet Kft., Hungary) in 1000 L of drinking water. Lacto-Immuno-Vital® was administered daily from the first day (D1) to D7 of the experiment. From D7 to D22 it was given in a pulsed manner (every third day) at a dose of 300 g in 1000 L of drinking water. Control group received only the standard diet. For immune analyses 6 randomly chosen chickens from experimental and control group were taken from the halls. The sampling days were set at D8 and D22 of the experiment. Samples of peripheral blood were collected from vena subclavia. The chickens were euthanized and whole jejunum was taken during necropsy into Hanks ice solution (pH 7.2-7.3). Administration of Lacto-Immuno-Vital in drinking water of non-stressed broilers during fattening period in commercial production increased phagocytic activity and phagocytic index. The number of IgA+ and CD8+ cells in lamina propria of intestine was decreased in chickens fed diet supplemented with Lacto-Immuno-Vital in drinking water. We suggest that increased phagocytic activity and decreased number of immunocompetent cells in mucosa of intestine was caused by improved systemic and local immune system function.
This study was aimed to evaluate the immunomodulatory, growth promoting and protective effects of aqueous (AE) and
ethanolic extracts (EE) of Ficus religiosa L. against coccidiois is in broilers. The F. religiosa bark was used to prepare AE and
EE. Immunomodulatory effects were demonstrated by lymphoblastogenic response to Phytohemagglutinin-P (PHA-P) and
humoral response to sheep erythrocytes. Feed conversion ratios were calculated as an indicator of growth performance. The
protective effects were assessed in broilers experimentally infected with Eimeria species (a mix of local isolates). Results
revealed significantly elevated lymphoblastogenic responses (p<0.05) in AE and EE inoculated broilers as compared to control
group. The antibody titers (Total, IgG and IgM) were also higher in experimental groups inoculated with Ficus derived extracts
as compared to control. Significantly improved FCR values (p<0.05) were recorded in groups inoculated with AE and EE of
F. religiosa. In challenge experiment, higher protection rates (50-70%) were observed in birds inoculated with Ficus extracts
as compared with those of control group (35%). Further, higher percent protections against gut (caecal and intestinal) lesions
were observed in groups inoculated with Ficus extracts when compared with control group. Moreover, statistically lower
(p<0.05) oocysts counts and higher (p<0.05) daily weight gains were also recorded in groups inoculated with Ficus extracts as
compared to control group. In conclusion, Ficus derived AE and EE revealed immunostimulatory and growth promoting effect
with subsequent protective efficacies against coccidiosis in broilers.
The effects of Lacto-Immuno-Vital synbiotic preparation on gene expression of IgA, MUC-2, and growth factor IGF-2 in the jejunum and on BW gain in broiler chickens were studied. A flock of 64,400 1-day-old Hybrid ROSS 308 chickens was inducted in the 42-day experiment. The chickens were divided into 2 equally size groups in separate halls. The chickens in the experimental (E) group received 500 g of Lacto-Immuno-Vital in 1,000 L of drinking water. The preparation was administered daily from the first day (day 1) to day 7 of the experiment. From day 7 to day 22, it was given in pulsed manner (every third day) at a dose of 300 g in 1,000 L of drinking water. The broiler chickens in the E group gained more weight (P < 0.001) compared with control from day 10 to day 42. Death of animals during feeding period was 1,078 chickens in the E group compared with 1,115 dead chickens in the control group. Feed conversion ratio was 1.61 kg of supplemented diet/kg of BW in the E group compare with 1.67 kg of nonsupplemented diet/kg of BW in control. The relative expression of IgA gene in the jejunum was upregulated on day 22 in the E group compared with control (P < 0.05), whereas relative expression of MUC-2 gene was upregulated in the E group compared with control on day 8 and day 22 (P < 0.05; P < 0.001). Similarly, relative expression of IGF-2 gene was upregulated in the E group compared with control on both samplings (P < 0.01). The composition of Lacto-Immuno-Vital synbiotic preparation showed beneficial effects on growth performance, feed conversion ratio, morbidity, mortality, and selected parameters of mucosal immunity in the chicken jejunum.
Microbial cell wall is mostly synthesized by the glycosylated proteins with the distinct enzymatic activity. In this review we have concentrated on the description of the certain steps of glycosylation and their effect on the cell wall integrity and yeast to hyphae transition, the process enhancing the pathogenic properties of C.albicans. The glycoproteins play an invaluable role in C. albicans virulence and they modulate adhesive, invasive, morphogenetic and immune stimulating properties of the pathogen as well as its susceptibility to the antifungal agents. Therefore, understanding of C. albicans glycobiology might let us expand the arsenal in the war against fungal enemies. The early stages of NO O-glycans and GPI-anchor synthesis requires dolichol-the lipid carrier of sugar residues. Diminished supply of dolichol causes series of defects in C. albicans cells, among which aberrant protein glycosylation is the most evident. Furthermore, the relations between the cell wall composition and integrity, resistance to some antifungal and cell wall disturbing agents and dolichol dependent glycosylation are observed. Moreover relevance of these reactions for the morphological differentiation of C.albicans is described.
The gastrointestinal epithelium is covered by a protective mucus gel composed predominantly of mucin glyco-proteins that are synthesized and secreted by goblet cells. Changes in goblet cell functions and in the chemical composition of intestinal mucus are detected in response to a broad range of luminal insults, including alterations of the normal microbiota. However, the regulatory networks that mediate goblet cell responses to intestinal insults are poorly defined. The present review summarizes the results of developmental, gnotobiotic, and in vitro studies that showed alterations in mucin gene expression, mucus composition, or mucus secretion in response to intestinal microbes or host-derived inflammatory mediators. The dynamic nature of the mucus layer is shown. Available data indicate that intestinal microbes may affect goblet cell dynamics and the mucus layer directly via the local release of bioactive factors or indirectly via activation of host immune cells. A precise defini-tion of the regulatory networks that inteface with goblet cells may have broad biomedical applications because mucus alter-ations appear to characterize most diseases of mucosal tissues.
Use of antibiotics as an additive in poultry diets to improve growth has been discussed in relation to bacterial resistance and the development of new products and management practices. This study was carried out to test the efficacy of a new substance (Saccharomyces cerevisiae cell walls, var. Calsberg- SCCW) obtained from the brewery industry, added (at 0.1 and 0.2%) to broiler chicken diets (based on corn and soybean meal), on performance and intestinal mucosa development In Experiment 1 (carried out in litter-floor pens) the results revealed higher body weight gain for the total experimental period and higher villus height at 7 d of age for the birds fed 0.2% SCCW. In a field test using 44,000 broilers that received feed containing 0.2% SCCW, the results also showed higher body weight gain and better feed conversion for SCCW-supplemented birds. The present findings show that SCCW improved body weight gain in broiler chickens and that this effect can be attributed to the trophic effect of this product on the intestinal mucosa, because it increases villus height, particularly during the first 7 d of a chicken's life.
This study was conducted to investigate antimicrobial resistance profiles of Escherichia coli isolates from broiler chickens in Alberta, Canada. Cecal contents of broiler chickens from 24 flocks were collected at slaughter between January and March 2005 for culture and antimicrobial susceptibility testing against a panel of 15 antimicrobials using a broth microdilution technique. Of 600 E. coli isolates tested, 475 (79.2%) were resistant to one or more antimicrobials, 326 (54.3%) were resistant to three or more antimicrobials, 65 (10.8%) were resistant to five or more antimicrobials, and 15 (2.5%) were resistant to seven or more antimicrobials. The most common resistance was to tetracycline (69.2%), followed by streptomycin (48.2%), kanamycin (40.3%), and sulfisoxazole (38.0%). None of the E. coli isolates were resistant to amikacin, ceftriaxone, or ciprofloxacin. Of the isolates that were resistant to two or more antimicrobials, the most common multidrug resistance patterns were streptomycinte-tracycline (44.0%), streptomycin-sulfisoxazole-tetracycline (30.7%), and kanamycin-streptomycin-sulfisoxazole-tetracycline (23.5%). Resistance to tetracycline and kanamycin (odds ratio = 46.7, P = 0.0001) was highly associated, followed by resistance to streptomycin and sulfisoxazole (odds ratio = 12.0, P = 0.0001), and streptomycin and tetracycline (odds ratio = 10.3, P = 0.0001). The flock level prevalence of resistance varied from 16.7% for chloramphenicol to 100.0% for ampicillin, streptomycin, sulfisoxazole, and tetracycline. The results of this study provided baseline information on antimicrobial susceptibility of E. coli isolates of broiler chickens at slaughter in Alberta, which can serve as a bench mark for future research.
This study investigated the protective effect of β-1,3/1,6-glucan on gut morphology, intestinal epithelial tight junctions,
and bacterial translocation of broiler chickens challenged with Salmonella enterica serovar Typhimurium. Ninety Salmonella-free Arbor Acre male broiler chickens were randomly divided into 3 groups: negative control group (NC), Salmonella Typhimurium-infected positive group (PC), and the Salmonella Typhimurium-infected group with dietary 100 mg/kg of β-1,3/1,6-glucan supplementation (T) to determine the effect of β-1,3/1,6-glucan
on intestinal barrier function. Salmonella Typhimurium challenge alone significantly decreased villus height (P < 0.001), villus height/crypt depth ratio (P < 0.05), and the number of goblet cells (P < 0.001) in the jejunum at 14 d postinfection (dpi), but significantly increased the number of intestinal secretory IgA (sIgA)-expressing
cells at 14 dpi (P < 0.01) and total sIgA levels in the jejunum at 7 (P < 0.05) and 14 dpi (P < 0.01) compared with the unchallenged birds (NC). Dietary β-1,3/1,6-glucan supplementation not only significantly increased
villus height, villus height/crypt depth ratio, and the number of goblet cells (P < 0.01), but also increased the number of sIgA-expressing cells (P < 0.05) and sIgA content in the jejunum at 14 dpi (P < 0.01) in birds challenged with Salmonella Typhimurium in comparison with Salmonella Typhimurium challenge alone. β-1,3/1,6-Glucan addition had significant inhibitory effects (P < 0.05) on cecal Salmonella colonization levels and liver Salmonella invasion of the Salmonella Typhimurium-infected birds compared with the PC group. Intestinal tight junction proteins claudin-1, claudin-4, and occludin
mRNA expression in the jejunum at 14 dpi was significantly decreased by Salmonella Typhimurium challenge alone (P < 0.01) compared with that of the NC group, whereas β-1,3/1,6-glucan supplementation significantly increased claudin-1 and
occludin mRNA expression (P < 0.01) at 14 dpi in the jejunum of the Salmonella Typhimurium-infected birds in comparison with the PC group. Our results indicate that dietary β-1,3/1,6-glucan can alleviate
intestinal mucosal barrier impairment in broiler chickens challenged with Salmonella Typhimurium.
The study was carried out to evaluate the beneficial effects of supplemental zinc (Zn) on the intestinal mucosal barrier function in Salmonella enterica serovar Typhimurium-challenged broiler chickens in a 42-day experiment. A total of 336 1-day-old male Arbor Acres broiler chicks were assigned to eight treatment groups. A 4×2 factorial arrangement of treatments was used in a completely randomized experimental design to study the effects of levels of supplemental Zn (0, 40, 80 and 120 mg/kg diet), pathogen challenge (with or without S. Typhimurium challenge), and their interactions. S. Typhimurium infection caused reduction of growth performance (P<0.05) and intestinal injury, as determined by reduced (P<0.05) villus height/crypt depth ratio and sucrase activity in the ileum, increased (P<0.05) plasma endotoxin levels, and reduced (P<0.05) claudin-1, occludin and mucin-2 mRNA expression in the ileum at day 21. Zn pre-treatment tended to improve body weight gain (P=0.072) in the starter period, to increase the activity of ileal sucrase (P=0.077), to reduce plasma endotoxin levels (P=0.080), and to significantly increase (P<0.05) the villus height/crypt depth ratio and mRNA levels of occludin and claudin-1 in the ileum at day 21. The results indicated that dietary Zn supplementation appeared to alleviate the loss of intestinal mucosal barrier function induced by S. Typhimurium challenge and the partial mechanism might be related to the increased expression of occludin and claudin-1 in broiler chickens.
J. Inst. Brew. 115(2), 151–158, 2009 Much research has been carried out over the years examining cell wall glucans from Saccharomyces cerevisiae and this study further examines aspects of the binding of (1→4)-α-D-glucan in the yeast cell wall, using a number of isolation techniques as well as monoclonal antibodies able to recognize a mixed (1→4)-α-D-glucan/(1→6)-β-D-glucan. Extraction of purified glucan, from S. cerevisiae cell wall, with 0.1N HCl, at 80°C for 6 h, released into the solution (1→4)-α-D-glucan and (1→6)-β-D-glucan as the major polysaccharides, along with an insoluble pellet highly enriched in (1→3)-β-D-glucan. The released (1→4)-α-D-glucan was composed of a high molecular size >100 kDa fraction (7.2% w/w) and a medium 5–50 kDa polysac-charide (10.2% w/w), with the (1→4)-α-D-glucan covalently bound to the (1→6)-β-D-glucan. The average molar ratio of the α:β glucan was 47: 53 in this mixed polysaccharide. The struc-ture of this polysaccharide was different from the structure of plant starch or animal glycogen as monoclonal antibodies spe-cific to yeast (1→4)-α-D-glucan/(1→6)-β-D-glucan did not recognize the plant starch or animal glycogen standards. Abbreviations: BSA – Bovine Serum Albumin; D 2 O – deute-rium oxide (heavy water), d.w. – dry weight; DI – deionised water; GEM – Glucan Enriched Material, HRP – Horse Radish Peroxidase.
In search of substances to replace antibiotics as growth promoters for farm animals, mannanoligosaccharides (MOS) have been proposed as a possible alternative. In the present experiment, the influence of MOS on growth performance and bacteriological, morphological, and functional aspects of small intestine was investigated in broiler chickens at different ages. Three dietary treatments were used: a negative control without MOS or antibiotic, a positive control (Zn bacitracin), and 2 g of MOS/kg of diet. The MOS supplement tended to improve BW gain compared with the negative control in early life ( P=0.07). The counts of total anaerobic bacteria, lactic acid bacteria, and Clostridium perfringens were not affected by the supplementation of MOS. The counts of coliform bacteria were increased in young birds treated with MOS. No significant differences in the gut morphology and function were noticed between the MOS treatment and the negative or the positive control at d 14, but birds in the positive control group had significantly higher jejunal villi and mucosal alkaline phosphatase activities than MOS-supplemented birds at d 35. In the current study conducted under hygienic experimental conditions, the addition of MOS did not show a clear positive effect on performance or intestinal morphology and function.
Secretory IgA (SIgA) serves as the first line of defense in protecting the intestinal epithelium from enteric toxins and pathogenic microorganisms. Through a process known as immune exclusion, SIgA promotes the clearance of antigens and pathogenic microorganisms from the intestinal lumen by blocking their access to epithelial receptors, entrapping them in mucus, and facilitating their removal by peristaltic and mucociliary activities. In addition, SIgA functions in mucosal immunity and intestinal homeostasis through mechanisms that have only recently been revealed. In just the past several years, SIgA has been identified as having the capacity to directly quench bacterial virulence factors, influence composition of the intestinal microbiota by Fab-dependent and Fab-independent mechanisms, promote retro-transport of antigens across the intestinal epithelium to dendritic cell subsets in gut-associated lymphoid tissue, and, finally, to downregulate proinflammatory responses normally associated with the uptake of highly pathogenic bacteria and potentially allergenic antigens. This review summarizes the intrinsic biological activities now associated with SIgA and their relationships with immunity and intestinal homeostasis.
Salmonella infections can cause a range of intestinal and systemic diseases in human and animal hosts. Although some Salmonella serovars initiate a localized intestinal inflammatory response, others use the intestine as a portal of entry to initiate a systemic infection. Considerable progress has been made in understanding bacterial invasion and dissemination strategies, as well as the nature of the Salmonella-specific immune response to oral infection. Innate and adaptive immunity are rapidly initiated after oral infection, but these effector responses can also be hindered by bacterial evasion strategies. Furthermore, although Salmonella resides within intramacrophage phagosomes, recent studies have highlighted a surprising collaboration of CD4 Th1, Th17, and B-cell responses in mediating resistance to Salmonella infection.
In this study, Salmonella enterica serovar Typhimurium challenge models were tested to identify the best conditions under which to perform the experimental infection of 3-wk-old broilers. Such a model would be useful to study the efficiency of therapeutic treatments that could take place at the end of the grow-out period. Salmonella-free chicks were obtained from a breeder flock vaccinated with Salmonella. Intestinal maternal immunity was monitored by ELISA analyses at 2, 9, and 16 d of age. Data indicated that protection of maternal origin was not maintained over time and was drastically reduced at 9 d of age (P < 0.01). At 21 d of age, chickens were orally inoculated with Salmonella Typhimurium. The effects of the oral challenge dose (0, 3 × 10(3), 3 × 10(6), and 3 × 10(9) cfu/bird) and vancomycin pretreatment (no administration or 25 mg/bird) on intestinal immune responses, growth performance, and Salmonella colonization of chickens were investigated. After infection, the mucosal immune response was rapid, with increased (P < 0.01) anti-Salmonella Typhimurium IgA titers measured at 8 d postinfection in intestinal contents. A linear relationship (P < 0.05) existed between specific IgA levels in intestinal and cecal contents and the challenge dose inoculated. None of the challenge protocols caused mortality or clinical symptoms after infection. Nevertheless, the experimental infection induced a significant deterioration of growth performance. The pretreatment with 25 mg of vancomycin at 3 h before Salmonella inoculation was able to establish stable infection rates among the population of 3-wk-old infected chickens. Nevertheless, Salmonella shedding was not stable over the rearing period, and the bacteria seemed to be naturally eliminated from most birds at 22 d postinfection. This natural clearance of the gut, which was related, at least in part, to the intestinal immune response, should limit the usability of the created mature challenge model within 1 to 2 wk after inoculation.
Escalating consumer concerns regarding pathogen resistance have placed the poultry industry under mounting pressure to eliminate the use of chemotherapeutic agents as feed additives. One possible alternative receiving increased attention is the use of immunomodulators such as β-glucan. A study was conducted to investigate the effects of a yeast-derived β-glucan (Auxoferm YGT) on broiler chick performance, lesion scores, and immune-related gene expression during a mixed Eimeria infection. Day-old chicks were fed diets containing 0, 0.02, or 0.1% YGT. On d 8 posthatch, one-half of the replicate pens were challenged with a mixed inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Measurements were taken and samples collected on d 4, 10, 14, and 21 posthatch. Dietary supplementation had no effect on performance or mortality. On d 14, 3 birds per pen (n = 24/treatment) were scored for intestinal coccidia lesions. Gross lesion severity was significantly reduced in birds supplemented with 0.1% YGT. On d 10, inducible nitric oxide synthase (iNOS) expression was downregulated in the jejunum of challenged birds fed 0.1% YGT. Expression of iNOS in the ileum was downregulated in the nonchallenged birds, but upregulated in the challenged birds fed 0.1% YGT on d 14. Interleukin (IL)-18 was upregulated in the jejunum of 0.1% YGT-treated birds. Interferon (IFN)-γ expression was decreased in challenged and nonchallenged birds fed 0.1% YGT. The IL-4 expression was downregulated in the nonchallenged birds with 0.1% YGT diet supplementation. The IL-13 and mucin-1 levels were also reduced due to β-glucan supplementation. Mucin-2 expression was increased in the nonchallenged birds, but decreased in the infected birds fed 0.1% YGT. These results suggest that although Auxoferm YGT at doses of 0.02 and 0.1% does not influence performance, it significantly reduces lesion severity and is capable of altering immune-related gene expression profiles, favoring an enhanced T helper type-1 cell response during coccidiosis.
During the first week posthatch, the avian immune system is immature and inefficient at protecting chicks from invading pathogens. Among immunomodulators, β-glucans are known as biological response modifiers due to their ability to activate the immune system. Current research suggests that β-glucans may enhance avian immunity; however, very little is known about their influence on regulation of immune function. A study was performed to evaluate the effects of dietary β-glucan on growth performance, immune organ weights, peripheral blood cell profiles, and immunerelated gene expression in the intestine. One-day-old chicks were fed a diet containing 0, 0.02, or 0.1% yeast β-glucan (n = 30/treatment). On d 7 and 14 posthatch, body and relative immune organ weights were measured and small intestinal sections were collected to evaluate gene expression by quantitative real-time PCR. Peripheral blood samples were also collected to determine heterophil:lymphocyte ratios. Supplementation of β-glucan did not significantly affect BW gains, and no significant differences were observed among groups for relative immune organ weights or heterophil:lymphocyte ratios. Compared with controls, expression of interleukin (IL)-8 was downregulated in the β-glucan-treated groups on d 7 and 14. On d 14, β-glucan inclusion resulted in increased inducible nitric oxide synthase expression. Expression of IL-18 was upregulated on d 7 but reduced on d 14 due to β-glucan supplementation. On d 7, interferon-γ and IL-4 expression decreased in the β-glucan-treated groups. However, on d 14, IL-4 expression was upregulated in the supplemented groups. Intestinal expression of IL-13 was also downregulated in the β-glucan-treated birds on d 7. These results suggest that dietary inclusion of β-glucans altered the cytokinechemokine balance; however, it did not elicit a robust immune response in the absence of a challenge, resulting in no deleterious effects on performance.
Live broiler chickens are important in the transmission of Salmonella to humans. Reducing Salmonella levels in the intestine of broiler chickens, in part, requires understanding of the interactions between Salmonella and the intestinal barriers that represent the first line of defense. Such barriers include the mucus layer (composed of mucins secreted by goblet cells) and the underlying epithelium. Two experiments were conducted to evaluate the effect of Salmonella Typhimurium infection on intestinal goblet cell dynamics (density and size) and villous morphology in broiler chicks. In Experiment 1, broiler chicks were either challenged with sterile media (control treatment) or orally given 7.4 x 10(7) colony-forming units (CFU) at 3 days of age (termed the CST treatment). Treatments were similar in Experiment 2, except that chicks in the CST treatment were challenged with 7.8 x 10(6) CFU at 4 days of age. Duration of each experiment was 14 days. At 7 days postchallenge (PC) in Experiment 1, jejunal tissue sections were collected, formalin-fixed, and routinely processed for histologic measurement of villous morphometric indices. In Experiment 2, at 10 days PC, jejunal tissue sections were collected and processed for histologic determination of goblet cell numbers and size, in addition to villous measurements. Results showed that Salmonella Typhimurium infection increased goblet cell density, reduced villous surface area, increased the incidence of epithelial exfoliation, and increased the incidence of heterophil influx into the lamina propria (P < 0.05). It was concluded that Salmonella Typhimurium infection impacts goblet cell biology and exerts morphopathologic changes in the jejunum of broiler chicks.
Yeast extracts (YE) contain biological response modifiers that may be useful as alternatives to antibiotics for controlling pathogens in poultry production and mitigating the deleterious effects of production stressors. The objective of the present study was to determine the ability of a commercial dietary YE (Alphamune) to modulate the immune response in male turkey poults challenged with Escherichia coli and subjected to transport stress. Alphamune was added to turkey poult diets at 0, 500, or 1,000 g/ton. Poults were challenged by air sac injection with 60 cfu of E. coli at 1 wk of age. At 3 wk of age, these challenged birds were subjected to transport stress and birds were bled and necropsied the following morning. Blood cell numbers and percentages, hematological parameters, and clinical chemistry values were determined. Oxidative burst activity of isolated heterophils was measured using stimulation with phorbol myristate acetate and a 2',7'-dichlorofluorescein diacetate assay. Data were analyzed using GLM and least squares means procedures of the SAS program. The numbers and percentages of heterophils in peripheral blood were increased and their oxidative burst activity was stimulated by YE. The stress challenge dramatically increased oxidative burst and this increase was significantly modulated by YE treatment. Serum levels of calcium, phosphorus, and triglycerides were decreased and uric acid levels, erythrocyte numbers, hemoglobin, and hematocrit were increased by YE supplementation. Bacteria were isolated from the air sac and liver of a lower percentage of birds provided with YE. These results suggest that dietary YE has potential as a nonantibiotic alternative for decreasing bacterial pathogens in turkey production.
Three experiments were performed to assess the ability of a Lactobacillus plantarum probiotic combined with a xylanase to reduce the effects of Salmonella Typhimurium infection in broiler chickens from 1 to 30 or 42 d of age. Chicks were challenged at 3 d of age with 108 or 105 cfu Salmonella Typhimurium/chick. Four diets were studied: a wheat-based diet (C+) supplemented with 0.1 g/kg of xylanase (E) or 106 cfu/g of L. plantarum (P), or both (PE). Uninfected chicks fed the C diet were used as negative control (C−). Six or 8 chicks were housed per cage
with 9 cages/treatment. Growth performance and feed conversion ratio (FCR) were recorded weekly. In experiment 1, bacterial
enumeration in ceca was achieved using the fluorescent in situ hybridization technique. Salmonella enumeration was realized in excreta by microbiological cultures (experiments 2 and 3). Nutrient digestibilities and AMEn were determined in experiment 3 from d 35 to 39. Infection with Salmonella Typhimurium led to a significant decrease in the daily weight gain (DWG) by 23.6 to 32.8%, whereas FCR was increased by 1.0
to 19.7%. Chickens fed the PE diet showed significantly improved performance in comparison with C+ birds (DWG: +12.5% in experiment
1; FCR: −2.1 to 8.6%), and in comparison with the P and E treatments (DWG: +6.3 to 8.3% in experiment 1; FCR: −2.7 to 6.4%).
In experiment 3, the FCR was significantly improved by 3% with the PE diet in comparison with C− chickens. The PE combination
tended to restore a microflora similar to that of uninfected broilers, whereas the P and E diets had less of an effect on
the profile of bacterial communities. At slaughter age, Salmonella contamination was reduced by 2.00 and 1.85 log colony-forming units for the E and PE treatment, respectively. The PE diet
significantly reduced the crude fat digestibility by 9.2%, in comparison with the C+ chickens. These results suggest that
the combination between L. plantarum and a xylanase as feed additive could be effective for reduction of the detrimental effect after Salmonella Typhimurium infection of broilers.
The effects in broiler chicks of treatment with a competitive exclusion (CE) product, an experimental dietary probiotic, and the abiotic beta-glucan on cecal colonization, organ invasion, and serum and intestinal IgG and IgA levels to Salmonella challenge was evaluated. Four groups of 1-d-old chicks were treated by oral gavage on d 1 with an appropriate dose of a commercial CE product. Three groups received daily doses of probiotic, beta-glucan, or both, for 6 d. Three other groups were fed daily from d 1 onwards with probiotic, beta-glucan, or both. Subgroups of 30 chicks from each group were challenged on d 1, 9, 16, or 23 with 10(7) cfu/ mL of Salmonella Typhimurium (1769NR) and killed 7 d later. Control groups were maintained untreated and remained unchallenged (negative control), or were challenged with Salmonella Typhimurium (1769NR; positive control), as described above. Cecum, liver, and spleen samples were examined for the presence of Salmonella, whereas serum and intestinal fluid samples were assayed for total antibody (IgG and IgA) concentrations. Data were analyzed by 1-way ANOVA, and means were compared using Duncan's multiple range test. In comparison with other treatments, those involving CE product and beta-glucan, with or without probiotic during the first week, resulted in a superior inhibition of cecal colonization and organ invasion by Salmonella and also offered a higher level of protection (P < 0.05). During the second week, treatments containing experimental dietary probiotic and beta-glucan, with or without CE product, resulted in an inhibition of liver invasion (P < 0.05). The IgA levels were significantly higher (P < 0.05) in intestinal fluid compared with serum, whereas IgG had low levels. The results in the first and third week indicate that combination treatments involving CE product, probiotic, and beta-glucan are a more effective control of Salmonella colonization than the corresponding individual preparations.
Two experiments were carried out to evaluate the effect of dietary addition of yeast cell wall (YCW); beta-1, 3/1, 6-glucan (BG); and mannoprotein complex (MP) purified fractions in broilers. In experiment 1, there was a control diet and 5 experimental diets containing, respectively: 10 mg of avilamycin (AVI)/kg of feed, 500 mg of YCW/kg of feed, 95 mg of MP/kg of feed, 145 mg of BG/kg of feed, and 95 mg of MP plus 145 mg of BG/kg of feed. All birds were vaccinated via drinking water against Newcastle disease virus at 9 d of age. At 42 d, chickens fed AVI, YCW, MP + BG, and BG diets had similar BW not significantly different from chickens fed the control diet. The antibody response of Newcastle disease virus vaccine was not affected by any experimental treatment. Broilers fed MP + BG diet had greater thymus weights (P </= 0.05), as a percentage of BW than those from the control and AVI treatments, but similar with respect to YCW and BG treatments. In experiment 2, there was a group-fed basal diet and 3 additional experimental groups receiving the basal diet supplemented with, respectively: 500 mg of YCW/kg of feed, 190 mg of MP/kg of feed, and 227 mg of BG/kg of feed. At 42 d of age, no difference in broiler growth rates was observed. Samples of the jejunum were collected at 21 d of age to determine villus height. Significantly higher villus height was observed in YCW, MP, and BG groups compared with that of the control group. The relative percentage of liver weight (P </= 0.01) was lower in broilers fed YCW than in broilers fed the control diet, but no differences were observed in respect to chickens fed BG. Data of these studies suggested that the changes in thymus and liver relative weights and villus morphology of broilers were induced with the same intensity by the use of complete YCW, MP + BG, and BG supplements.
The effects of dietary supplementation of the direct-fed microbial (DFM) Primalac in mash or crumbled feed on histological and ultrastructural changes of intestinal mucosa was determined in 2 populations of poults; 1 with and 1 without a Salmonella spp. challenge. Three hundred thirty-six 1-d-old female Large White turkey poults were randomly distributed into 8 treatment groups with 6 replicates of 7 poults in each pen. The poults were placed on 1 of 4 dietary treatments in a 2 x 2 x 2 factorial arrangement (mash or crumble feed, with or without DFM, not-challenged or challenged at 3 d of age). The DFM groups were fed a Primalac-supplemented diet from d 1 until the last day of the experiment (d 21). At 3 d of age, 50% of the poults were challenged with 1 mL of 10(10) cfu/ mL of Salmonella spp. (Salmonella enterica serovar Typhimurium, Salmonella Heidelberg, and Salmonella Kentucky) by oral gavage. The inoculated poults were housed in a separate room from nonchallenged controls. Feed and water were provided ad libitum for all birds. At d 21, 1 poult per pen (total of 6 poults per treatment) was randomly selected and killed humanely by cervical dislocation. After necropsy, the small intestine was removed, and tissue samples from duodenum, jejunum, and ileum were taken for light and electron microscopic evaluation. The DFM birds showed increased goblet cell (GC) numbers, total GC area, GC mean size, mucosal thickness, and a greater number of segmented filamentous bacteria compared with controls. Changes in intestinal morphology as observed in this study support the concept that poultry gut health and function, and ultimately bird performance, can be improved by dietary supplementation with DFM products such as Primalac as used in this study.
Salmonella enterica serovar Enteritidis is the major zoonotic and intracellular pathogen. Different strategies have been developed to prevent the S. Enteritidis infection. The beta-1,3-1,6-glucan of Schizophyllum commune was used as an immunological booster to determine the minimal dietary level of beta-glucan that would restrict S. Enteritidis infection through the effects of beta-glucan on the activity of macrophages and direct physical protection of the intestine. One-day-old male Single Comb White Leghorn chicks were used in all trials. In trials 1 and 2, the 0.1% beta-1,3-1,6-glucan treatment completely eliminated the viable S. Enteritidis from spleen and liver in an oral challenge of 10(8) S. Enteritidis without any harmful effect on BW, serum proteins, and immunoglobulin. Instead of a 21-d feeding period of beta-glucan, a 14-d treatment was enough to eliminate the S. Enteritidis in spleen and liver. In trial 3, an increase in the relative weight of bursa of Fabricius and phytohemagglutinin-P-inducing cutaneous basophil hypersensitivity was observed (P < 0.05). In trials 2, 3, and 4, the direct or indirect effect of beta-1,3-1,6-glucan on abdominal macrophages was examined. Sterilized 3% Sephadex G-50 was injected to induce abdominal (peritoneal) phagocytes in chicks fed with or without 0.1% beta-1,3-1,6-glucan. Significantly increased phagocytic and bactericidal capability to S. Enteritidis was found in abdominal macrophages either pretreated or in vitro treated with 0.1% beta-1,3-1,6-glucan. In conclusion, in addition to the physical properties to block S. Enteritidis entrance, 0.1% dietary beta-1,3-1,6-glucan may enhance the host defense to S. Enteritidis by directly upregulating the phagocytosis and bactericidal activity of abdominal macrophages in chicks.
The immunogenicity of a tissue culture-derived vaccine generated from an Eimeria tenella-infected cell line in a serologically defined bird line, and the ability to confer protection against homologous challenge in young chicks was examined. The cell line, SB-CEV-1/F7, was infected with E. tenella sporozoites and the resulting 72-h postinfection cell-free supernatants were adjuvanted and used to immunize Leghorn chicks homozygous for the B19 haplotype. Peripheral blood and splenic lymphocytes from these immunized birds proliferated in vitro in response to both sporozoite and SB-CEV-1/F7 tissue culture-derived parasite antigens. In addition, splenic immune lymphocytes obtained from birds previously exposed to E. tenella in vivo responded to these tissue culture-derived parasite antigens in vitro. To evaluate the efficacy of the vaccine, B19B19 chicks were vaccinated s.c. with adjuvanted 72-h postinfection cell-free supernatants or an ammonium sulfate precipitate derivative thereof, orally boosted, and then subjected to homologous parasite challenge at 10 d of age. The level of protection (body weight gain, cecal lesions) was assessed 6 d after challenge. Performance results from four battery trials demonstrated that vaccinated birds were significantly protected against weight loss compared to unimmunized, challenged controls. In addition, in two of the four trials, vaccinated birds were significantly protected against lesions. These results provide strong evidence that tissue culture-derived parasite antigens obtained from the E. tenella-infected SB-CEV-1/F7 cell line are immunogenic in birds and can provide partial protection against E. tenella clinical coccidiosis.
The tight junction protein ZO-1 belongs to a family of multidomain proteins known as the membrane-associated guanylate kinase homologs (MAGUKs). ZO-1 has been demonstrated to interact with the transmembrane protein occludin, a second tight junction-specific MAGUK, ZO-2, and F-actin, although the nature and functional significance of these interactions is poorly understood. To further elucidate the role of ZO-1 within the epithelial tight junction, we have introduced epitope-tagged fragments of ZO-1 into cultured MDCK cells and identified domains critical for the interaction with ZO-2, occludin, and F-actin. A combination of in vitro and in vivo binding assays indicate that both ZO-2 and occludin interact with specific domains within the N-terminal (MAGUK-like) half of ZO-1, whereas the unique proline-rich C-terminal half of ZO-1 cosediments with F-actin. Consistent with these observations, we found that a construct encoding the N-terminal half of ZO-1 is specifically associated with tight junctions, whereas the unique C-terminal half of ZO-1 is distributed over the entire lateral surface of the plasma membrane and other actin-rich structures. In addition, we have identified a 244-amino acid domain within the N-terminal half of ZO-1, which is required for the stable incorporation of ZO-1 into the junctional complex of polarized MDCK cells. These observations suggest that one functional role of ZO-1 is to organize components of the tight junction and link them to the cortical actin cytoskeleton.
Infection of polarized MDCK epithelial layers by Salmonella enterica serovar Typhimurium is accompanied by increased tight junction permeability and by contraction of perijunctional actinomyosin.
We localized dysfunctional tight junctions in serovar Typhimurium-infected MDCK layers by imaging apical-basolateral intramembrane
diffusion of fluorescent lipid and found that loss of the apical-basolateral diffusion barrier (tight junction fence function)
was most marked in areas of prominent perijunctional contraction. The protein kinase inhibitor staurosporine prevented perijunctional
contraction but did not reverse the effects of serovar Typhimurium on tight junction barrier function. Hence, perijunctional
contraction is not required for Salmonella-induced tight junction dysfunction and this epithelial response to infection may be multifactorial.
Recent studies on the molecular pathogenesis of Salmonella enterica serotype Typhimurium-induced enterocolitis using tissue culture models and the neonatal calf model have led to an improved understanding of key events occurring during the complex series of host-pathogen interactions leading to diarrhea. In vitro studies show that Salmonella serovar Typhimurium translocates a number of type III secreted effector proteins, including SipA, SopA, SopB, SopD, and SopE2 into host cells. SipA, SopA, SopB, SopD, and SopE2 are required for eliciting infiltration of neutrophils in the calf model of enterocolitis, presumably by inducing the production of chemoattractant chemokines in bovine ileal tissue during Salmonella serovar Typhimurium infection. The resulting acute inflammatory response is associated with an increase in vascular permeability resulting in mucosal edema. Furthermore, the influx of neutrophils is associated with necrosis of the uppermost ileal mucosa. The injury to the intestinal epithelium leads to leakage of extravascular fluids and massive transmigration of neutrophils into the intestinal lumen, a process normally prevented by the epithelial permeability barrier. These data suggest that the severe fluid loss observed during Salmonella serovar Typhimurium-induced enterocolitis is at least in part due to an inflammatory mechanism which causes liquid to flow from the blood to the intestinal lumen.
The ability of fungal-derived beta-glucan particles to induce leukocyte activation and the production of inflammatory mediators, such as tumor necrosis factor (TNF)-alpha, is a well characterized phenomenon. Although efforts have been made to understand how these carbohydrate polymers exert their immunomodulatory effects, the receptors involved in generating these responses are unknown. Here we show that Dectin-1 mediates the production of TNF-alpha in response to zymosan and live fungal pathogens, an activity that occurs at the cell surface and requires the cytoplasmic tail and immunoreceptor tyrosine activation motif of Dectin-1 as well as Toll-like receptor (TLR)-2 and Myd88. This is the first demonstration that the inflammatory response to pathogens requires recognition by a specific receptor in addition to the TLRs. Furthermore, these studies implicate Dectin-1 in the production of TNF-alpha in response to fungi, a critical step required for the successful control of these pathogens.
Lentinan (LEN) is an intensively studied beta-glucan that has been shown to have immunostimulating and antitumor functions.
However, it currently is not used in veterinary practice and animal production. This study was conducted to investigate the
impacts of LEN on broiler splenocyte proliferation, interleukin-2 (IL-2) production, and to explore its effects on receptor
signal transduction by determining signaling molecules, including nitric oxide (NO), cytosolic-free Ca2+, cytosolic cyclic
adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP). The results showed that compared to the control
all three measured doses, including 40, 80, and 160 microg/mL LEN, increased splenocyte proliferation and IL-2 production
(P < 0.05). Lentinan increased splenocyte NO production and cytosolic-free calcium concentration in a dose-dependent manner
(P < 0.001). After incubating splenocytes for 20 min, LEN increased intracellular cAMP and cGMP concentrations at a dose of
80 and 160 microg/mL, respectively. However, after incubating the splenocytes for 60 min, LEN had no effect on cytosolic cAMP
and cGMP concentration irrespective of the LEN dosage. Those results indicated that LEN had immunostimulatory effects on splenocytes
by increasing splenocyte proliferation and IL-2 production and by activating splenocyte receptor signal transduction.
Salmonella enterica serovar Typhimurium (S. Typhimurium) infections cause systemic disease in the young chick, whereas in the older chicken the infection is mainly restricted to the intestine. Chickens infected orally with S. Typhimurium (F98) at 6 weeks of age and re-infected 10 weeks later were monitored for antibody production, T-cell proliferation and production of selected cytokines (interferon-gamma, interleukin-1beta and transforming growth factor-beta(4)). A strong coordinated antigen-specific humoral and cellular immune response was temporally linked to resolution of the primary infection. Enhanced levels of mRNA encoding the cytokines, interleukin-1beta, transforming growth factor-beta(4) and interferon-gamma were also evident during early phases of primary infection. Secondary infection was restricted to the intestine and of shorter duration than primary infection. Splenic immune responses were not further enhanced by secondary infection; indeed, antigen-specific proliferation was significantly reduced at 1 day after secondary infection, which may be interpreted as the trafficking of reactive T cells from the spleen to the gut.
This study evaluated the efficacy of a yeast beta-glucan product (YBG) as a growth-promoting feed ingredient for broilers. Two trials were conducted with day-old chicks assigned to 24 pens (38 birds/pen) and one of three diets: no growth promotant, virginiamycin, or YBG. On days 14 and 38, two birds per pen were euthanized and the spleen and bursa of Fabricius were removed. In the first trial, body weights of birds from each treatment were the same until 38 d, when control birds were smaller (P<0.05). In the second trial, 38-d body weights were the same for all treatments. A third trial was conducted with half the number of pens per treatment. In the third trial, controls were smaller than YBG at 38 d, but not smaller than virginiamycin. Feed conversion was not affected by diet in trials 2 and 3 but for trial 1 the control birds had poorer conversion than virginiamycin (P<0.05), but not worse than YBG. Spleen weights were not different between treatment groups. Bursa weights decreased with age for all treatments in trials 2 and 3, but not in trial 1 for controls. These results indicate that YBG is as effective as virginiamycin in promoting growth of broiler chickens.
The object of this trial was to investigate the effect of dietary β-1,3/1,6-glucan supplementation on the performance and immunological response of broiler chickens. Two hundred and forty 1-day old male broilers (39±1 g) were separated into six treatments which were given six different feeds containing 0 (control), 25, 50, 75, 100 and 125 mg/kg dietary β-1,3/1,6-glucan supplementation. On days 21 and 42, body weight gain, feed consumption and feed conversation rate were recorded as measures of growth performance. The levels of key cytokines in the immuno-regulating pathway: interleukin-1 (IL-1), interleukin-2 (IL-2), interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), and the concentrations of signal molecules: peripheral blood plasma globulin, serum Immunoglobulin G (IgG) and intestinal secretary Immunoglobulin A (sIgA), were measured as indices of the immune response to determine suitable levels of dietary β-1,3/1,6-glucan supplementation. The results indicated that performance was elevated quadratically with dietary β-1,3/1,6-glucan supplementation. Maximal growth performance and an enhanced immunological response were obtained at a supplemented level of 50 mg/kg.
The yeast cell wall of Saccharomyces cerevisiae is an important source of β-D-glucan, a glucose homopolymer with many functional, nutritional and human health benefits. In the present study, the yeast cell wall fractionation process involving enzymatic treatments (savinase and lipolase enzymes) affected most of the physical and functional characteristics of extracted fractions. Thus, the fractionation process showed that β-D-glucan fraction F4 had significantly higher swelling power and fat binding capacity compared to other fractions (F1, F2 and F3). It also exhibited a viscosity of 652.12 mPa s and a high degree of brightness of extracted β-D-glucan fraction. Moreover, the fractionation process seemed to have an effect on structural and thermal properties of extracted fractions. Overall, results showed that yeast β-D-glucan had good potential for use as a prebiotic ingredient in food, as well as medicinal and pharmaceutical products.
β-Glucan is a cell wall component that is one of the most plentiful cell polysaccharides. Moreover, it has been found to have several beneficial effects on the immune system. In yeast, β-glucan is mainly contained in the yeast cell wall, and thus it is important to produce high levels of cell mass for the mass production of yeast β-glucan. Response surface methodology (RSM) offers a potential means of optimizing process factors and medium components; it has been used to estimate the effects of medium components on cell mass production. In the present study, the optimal concentrations of molasses and corn steep liquor (CSL) in the medium were determined to be 6.4% (v/v) and 17% (v/v). The cell mass predicted by statistical analysis was 9.76 g/L after 20 h of cultivation. In a 2.5-L stirred tank reactor (STR), the cell mass produced in a batch culture was 36.5-39.3 g/L. The maximum cell mass in the fed-batch cultures of Saccharomyces cerevisiae JUL3 was 95.7 g/L using 50% molasses solution and a feed rate of 10 mL/h. The cell mass obtained in the fed-batch culture was 2.4-fold higher than that obtained in the batch culture.
This experiment was conducted to investigate the effects of Lactobacillus acidophilus on performance, carcass characteristics, blood parameters, and intestinal microflora of broiler chicks. The dietary treatments were: basal diet as control 1; basal diet plus 1g. kg -1 of a commercial probiotic Bioplus2; basal diet plus 10 and 20 g kg -1 fermented milk that contained 2×10 8 cfu g -1 Lactobacillus acidophilus. To evaluate the effect of water alone on chick performance, equal volume of water in 20 g fermented milk was added to each kg of the basal diet (control 2). A total of 280 one-day old male broiler chicks were randomly allocated to 5 experimental groups of 4 replicates of 14 chicks each. The chicks were grown to 42 d of age. The result of the experiment indicated that feed intake in chicks fed diet supplemented with commercial probiotic was significantly higher than L. acidophilus probiotic. Weight gain for the chicks fed with the diet that contained 20 g kg -1 fermented milk was higher than the control chicks, in the first 3 weeks. There was no significant difference in feed conversion and weight of organs. The number of Lactobacilli in ileum and colon were higher in L. acidophilus treated birds than the control group and also the number of Coliforms was lower, but the effects were not statistically significant. The levels of blood cholesterol, alanine aminotransferase, aspartate aminotrasferase and alkaline phosphatase were the highest in the control group, but the effect was statistically significant only for ALT measured at 21 d of age.
Beta‐1,3/1,6‐glucan (β‐glucan) was tested as a possible immunomodulator. Chicken macrophages from a macrophage cell line MQ‐NCSU and from abdominal exudate of broiler chickens were exposed to various concentrations of β‐glucan in vitro. In addition, day‐old broiler chicks were fed a diet containing 0, 20, and 40 mg/kg β‐glucan in the starter and 0, 20, and 20 mg/kg in the grower diet. Several baseline immune parameters were examined following such exposures. The results showed that β‐glucan exposure increased nitrite and interleukin‐1 (IL‐1) production as well as induced macrophage to proliferate in culture. However, IL‐6 production was not affected. Dietary β‐glucan supplementation increased the macrophage phagocytic activity, anti‐sheep red blood cells antibody response post‐boost, as well as the PHA‐P‐mediated lymphoproliferative response measured as a toe‐web swelling. The percentage of CD4+, CD8+, and CD4+/CD8+ double positive lymphocytes in the intestinal intraepithelial leukocytes was increased in β‐glucan supplemented chicks. Furthermore, the primary and secondary lymphoid organs such as bursa of Fabricius, thymus and spleen were larger in β‐glucan‐supplemented chicks as compared to the chicks on basal diet. The findings of these studies which showed that β‐glucan improves several base‐line immune responses in the chicken imply that β‐glucan can be used as a possible immunomodulator in food animals such as the chicken.
β-Glucans are structural cell wall polymers of many fungi which possess immunomodulatory activities. Although the therapeutic benefits associated with these compounds, particularly as anti-infective and antitumorigenic agents, have led to a large body of published research over the last five decades, it is still unclear how these carbohydrates mediate their effects. Recent studies, however, are starting to shed some light on the cellular receptors and molecular mechanisms involved, which also have direct relevance on the innate immune response to fungal pathogens.
1. This study was conducted to evaluate the effects of dietary β-glucan and kefir (a fermented milk product) on growth performance, blood profiles, relative organ weight and meat quality in broilers.
2. A total of 375 day-of-hatch mixed sex ROSS 308 broilers (BW of 46 ± 0.1 g) were used in a 5-week experiment and randomly allotted to one of the following dietary treatments: (1) NC, basal diet; (2) PC, basal diet + 40 mg/kg of avilamycin; (3) B, NC + 0.1% β-glucan; (4) K, NC + 0.1% kefir; (5) BK, NC + 0.1% β-glucan + 0.1% kefir.
3. During weeks 0–3, broilers in B, K and BK treatments had higher body weight gain (BWG) than those in NC treatment. During weeks 4–5, BK treatment had a higher BWG than NC treatment. Overall, broilers given PC, K and BK diets had higher BWG than those given NC diet. The feed efficiency ratio (FCR) was improved by PC treatment.
4. Relative liver weight was increased by B treatment, whereas the relative weight of breast meat and gizzard was higher in BK group than that in NC group. Broilers given PC, B and BK diets had greater breast meat redness value and reduced drip loss at d 5 and d 7. The cooking loss was also reduced by B and BK treatments compared with NC treatment.
5. In conclusion, the results suggested that inclusion of 0.1% β-glucan and 0.1% kefir, either individually or combined, would improve growth performance and benefit meat quality in broiler chickens.
1,3-β-d-glucan is a widespread polysaccharide in microorganisms, mushrooms and plants. Numerous benefits for the health of humans and animals have been described for more than 50 years. One readily available source for 1,3-β-d-glucan is the cell wall of the common baker's or brewer's yeast Saccharomyces cerevisiae. Conventional isolation processes involving treatments with hot alkali and acids, however, cause a certain degradation of the polymeric chains resulting not only in reduced yields but also a possible weakening of the beneficial effects. We have developed a new non-degrading process for the isolation of glucan from yeast cell walls comprising gentle extraction steps and enzymatic treatments without any extreme pH values. Depending on the quality of the utilized yeast cell walls, 1,3-β-d-glucan is obtained in a purity of up to 92% and a yield of 87%. During this process, the valuable byproduct mannoprotein—also beneficial for health—is easily obtained.
To review recent findings dealing with the involvement of mucosal immunoglobulin A (IgA) in the gut barrier function and various gastrointestinal diseases. New information will be discussed in the context of previous knowledge in this field.
The epithelial barrier function seems to be central in many mucosal disorders because it is decisive for host-microbial interactions and penetration of soluble antigens into the lamina propria. Secretory IgA contributes to the barrier function and recent evidence strongly supports the notion that such antibodies are involved in immunological homeostasis.
Inflammatory bowel disease involves a break of tolerance to the commensal microbiota. Aberrations in the mucosal IgA system may, therefore, be part of the inflammatory bowel disease pathogenesis. In gluten-induced enteropathy, however, it has been suggested that a mucosal IgA response may promote the progression of celiac disease and dermatitis herpetiformis by enhancing the uptake of gluten peptides and inhibiting the enzyme activity of tissue transglutaminase. A mucosal IgA response may also promote gastritis by protecting Helicobacter pylori from complement attack. In food allergy, several facets of the epithelial barrier function may show deficiency, including secretory IgA.
Mucosal surfaces are lined by epithelial cells. These cells establish a barrier between sometimes hostile external environments and the internal milieu. However, mucosae are also responsible for nutrient absorption and waste secretion, which require a selectively permeable barrier. These functions place the mucosal epithelium at the centre of interactions between the mucosal immune system and luminal contents, including dietary antigens and microbial products. Recent advances have uncovered mechanisms by which the intestinal mucosal barrier is regulated in response to physiological and immunological stimuli. Here I discuss these discoveries along with evidence that this regulation shapes mucosal immune responses in the gut and, when dysfunctional, may contribute to disease.
Global broiler chicken pen trial reports (1993-2003) were analyzed statistically to determine effects of Saccharomyces cerevisiae var. boulardii yeast outer cell wall mannan oligosaccharide (MOS; Bio-Mos®, Alltech, Nicholasville, Kentucky USA) supplemented diets versus negative control (nCON) or antibiotic-supplemented positive control (pCON) diets. Criteria for selecting studies were: 1) pen trial, 2) written report, 3) MOS fed for entire study period, 4) negative and/or positive control, 5) antibiotic stated (for positive control), 6) replication and 7) age, body weight (BWT) and feed conversion ratio (FCR) given. Mortality (MORT) was used when reported. Results were averaged "by treatments" (all comparisons) and "by trials" (comparisons averaged by trial before analysis) using Paired T-test to compare nCON and pCON means with corresponding MOS means. Slightly different answers but similar patterns emerged by these methods. Considering results averaged by trials, MOS diets gave the following relative improvements compared to nCON diets: BWT, +1.61%; FCR, -1.99% and MORT, -21.4 (all significant at P = 0.020). Relative improvements using MOS feeds compared to the pCON diets were: BWT, -0.36% and FCR, -0.11% (P = 0.473; nonsignificant differences). The MOS diets significantly (P = 0.008) lowered mortality (-18.10%) relative to pCON diets, indicating a strong beneficial effect. The MOS diets produced BWT and FCR comparable to those of pCON diets but significantly lowered MORT compared to antibiotic diets. Currently recommended optimal MOS levels of addition for broiler chicken feeds are: 0.2%, 0 to 7 days; 0.1%, 7 to 21 days and 0.05%, 21 to 42 days (or market).
The intestinal epithelium is a single-cell layer that constitutes the largest and most important barrier against the external environment. It acts as a selectively permeable barrier, permitting the absorption of nutrients, electrolytes, and water while maintaining an effective defense against intraluminal toxins, antigens, and enteric flora. The epithelium maintains its selective barrier function through the formation of complex protein-protein networks that mechanically link adjacent cells and seal the intercellular space. The protein networks connecting epithelial cells form 3 adhesive complexes: desmosomes, adherens junctions, and tight junctions. These complexes consist of transmembrane proteins that interact extracellularly with adjacent cells and intracellularly with adaptor proteins that link to the cytoskeleton. Over the past decade, there has been increasing recognition of an association between disrupted intestinal barrier function and the development of autoimmune and inflammatory diseases. In this review we summarize the evolving understanding of the molecular composition and regulation of intestinal barrier function. We discuss the interactions between innate and adaptive immunity and intestinal epithelial barrier function, as well as the effect of exogenous factors on intestinal barrier function. Finally, we summarize clinical and experimental evidence demonstrating intestinal epithelial barrier dysfunction as a major factor contributing to the predisposition to inflammatory diseases, including food allergy, inflammatory bowel diseases, and celiac disease.
This study characterizes the transmigration of enteroinvasive Salmonella typhi in vitro, using a human intestinal epithelial cell line as a model of small intestinal epithelium. C2BBe cells, a subclone of CACO-2 with a highly differentiated enterocytic phenotype, were grown to maturity on Transwell filters. S. typhi Ty2 and the vaccine strain, Ty21a, the S. typhi mutant X7344 and parent strain SB130, and S. typhimurium 5771 in logarithmic phase were introduced to the upper chamber of the filter units. Numbers of bacteria in the lower chamber, TER and permeability of the monolayer to mannitol were measured over time. Monolayers were examined by light, electron and confocal microscopy to determine the pathway of bacterial transmigration, and intracellular bacteria were estimated by gentamicin assay. Epithelial cell injury was quantified by light microscopy. S. typhi transmigrated earlier and in larger numbers than S. typhimurium, inducing marked changes in electrical resistance and permeability. Unlike S. typhimurium, S. typhi selected epithelial cells in small number and caused their death and extrusion from the monolayers leaving holes through which S. typhi transmigrated. Ty2 consistently transmigrated in larger numbers and with more injury to monolayers than Ty21a. S. typhi crosses the monolayers of C2BBe cells by a paracellular route in contrast to the transcellular pathway described for other Salmonellae. This may be related to the unique pathophysiology of S. typhi infection and the restricted host specificity of this pathogen. In these assays the vaccine strain, Ty21a, is slightly less invasive than its parent, though more invasive than S. typhimurium.
In the mouse model of Salmonella typhimurium infection, the specialized antigen-sampling intestinal M cells are the primary route of Salmonella invasion during the early stages of infection. Under certain experimental conditions, M-cell invasion is accompanied by M-cell destruction and loss of adjacent regions of the follicle-associated epithelium (FAE), although the conditions responsible for expression of the cytotoxic phenotype in a proportion of previous studies have not been defined. In the present study, we have demonstrated that the cytotoxic effect exerted by wild-type S. typhimurium on mouse Peyer's patch FAE is dependent on the inoculum composition. We have also demonstrated that the extent of FAE destruction correlates with the extent of M-cell invasion. Bacteria inoculated in Luria-Bertani (LB) broth induce extensive FAE loss and exhibit efficient M-cell invasion, whereas bacteria inoculated in phosphate-buffered saline fail to induce significant FAE disruption and invade M cells at significantly lower levels. Similarly, inoculation in LB significantly enhances invasion of Madin-Darby canine kidney cells by wild-type S. typhimurium. Mutants defective for expression of invA, a component of Salmonella pathogenicity island 1 which is vital for efficient invasion of cultured cells, fail to induce FAE destruction and, when inoculated in LB, are attenuated for M-cell invasion. Variation in inv gene expression is, therefore, one possible mechanism by which inoculate composition may regulate the virulence of wild-type S. typhimurium. Our findings suggest that the composition of the gut luminal contents may be critical in determining the outcome of naturally acquired Salmonella infections and that both vaccine formulation and dietary status of vaccine recipients may significantly affect the efficacy and safety of live Salmonella oral vaccine delivery systems.
Studies of the impact of enteric pathogens and their virulence factors on the proteins comprising the tight junction and zonula adherens offer a novel approach to dissection of tight junctional complex regulation. Most studies to date provide only tantalizing clues that select pathogens may indeed assault the tight junctional complex. Information on critical human pathogens such as Campylobacter jejuni and Shigella and Salmonella subspecies is lacking. Mechanistic studies are currently sparse, but available results on pathogenic Escherichia coli and specific virulence factors such as the Rho-modifying and protease bacterial toxins indicate four major mechanisms by which these pathogens may act: 1) direct cleavage of tight junctional structural proteins; 2) modification of the actin cytoskeleton; 3) activation of cellular signal transduction; and 4) triggering transmigration of polymorphonuclear cells across the epithelial cell barrier. New therapeutics may evolve from detailed studies of these pathogens and the cellular processes and proteins they disrupt.
The common mucosal immune system (CMIS) consists of an integrated cross-communication pathway of lymphoid tissues made up of inductive and effector sites for host protection against pathogenic microorganisms. Major effector molecules of the CMIS include IgA antibodies and cytokines, chemokines and their corresponding receptors. Secretory IgA (S-IgA), the major immunoglobulin, is induced by gut-associated lymphoreticular tissue (GALT)-derived B cells with the help of Th1- and Th2-type CD4(+) T lymphocytes. Cytotoxic T lymphocytes (CTLs) in the mucosal epithelium, a subpopulation of intraepithelial lymphocytes (IELs), also help maintain the mucosal barrier. The CMIS is unique in that it can provide both positive and negative signals for the induction and regulation of immune responses in both the mucosal and systemic compartments after oral or nasal antigen exposure. Prevention of infection through mucosal surfaces can be achieved by the CMIS through connections between inductive (e.g. GALT) and effector tissues. When vaccine antigens are enterically administered together with mucosal adjuvants [e.g. cholera toxin (CT), heat-labile toxin produced by Escherichia coli (LT) and IL-12], antigen-specific Th1/Th2 and IgA B cell responses are induced simultaneously in the mucosal effector compartment. Since these antigen-specific immune responses are not generated by oral vaccine without mucosal adjuvant, safe and effective adjuvants for the induction of antigen-specific S-IgA and CTL responses are essential for the development of mucosal vaccines for protection against infectious diseases. Finally, recent findings suggest the presence of a CMIS-independent IgA induction pathway, which also must be considered in the development of mucosal vaccines.
Tight junctions are one mode of cell–cell adhesion in epithelial
and endothelial cellular sheets. They act as a primary barrier to the diffusion
of solutes through the intercellular space, create a boundary between the
apical and the basolateral plasma membrane domains, and recruit various cytoskeletal
as well as signalling molecules at their cytoplasmic surface. New insights
into the molecular architecture of tight junctions allow us to now discuss
the structure and functions of this unique cell–cell adhesion apparatus
in molecular terms.
Inflammatory bowel disease (IBD) consisting of ulcerative colitis (UC) and Crohn's (CD) typically displays a waxing and waning course punctuated by disease flares that are characterized by transepithelial migration of neutrophils (PMN) and altered barrier function. Since epithelial barrier function is primarily regulated by the apical most intercellular junction referred to as the tight junction (TJ), our aim was to examine expression of TJ and adherens junction (AJ) proteins in relation to PMN infiltration in mucosal tissue samples from patients with active IBD. Expression of epithelial intercellular TJ proteins (occludin, ZO-1, claudin-1, and JAM) and subjacent AJ (beta-catenin and E-cadherin) proteins were examined by immunoflourescence/confocal microscopy, immunohistochemistry, and Western blotting. Colonic mucosa from patients with UC revealed dramatic, global down-regulation of the key TJ transmembrane protein occludin in regions of actively transmigrating PMN and in quiescent areas in the biopsy samples. Significant decreases in occludin expression were observed at the protein and mRNA levels by Western and Northern blotting. In contrast, expression of other TJ and AJ proteins such as ZO-1, claudin-1, JAM, beta-catenin, and E-cadherin were down-regulated only in epithelial cells immediately adjacent to transmigrating PMN. Analysis of inflamed mucosa from Crohn's disease patients mirrored the results obtained with UC patients. No change in TJ and AJ protein expression was observed in colonic epithelium from patients with collagenous colitis or lymphocytic colitis that are respectively characterized by a thickened subepithelial collagen plate and increased intraepithelial lymphocytes. These results suggest that occludin expression is diminished in IBD by mechanisms distinct from those regulating expression of other intercellular junction proteins. We speculate that down-regulation of epithelial occludin may play a role in enhanced paracellular permeability and PMN transmigration that is observed in active inflammatory bowel disease.
The cell wall of Saccharomyces cerevisiae is an elastic structure that provides osmotic and physical protection and determines the shape of the cell. The inner layer of the wall is largely responsible for the mechanical strength of the wall and also provides the attachment sites for the proteins that form the outer layer of the wall. Here we find among others the sexual agglutinins and the flocculins. The outer protein layer also limits the permeability of the cell wall, thus shielding the plasma membrane from attack by foreign enzymes and membrane-perturbing compounds. The main features of the molecular organization of the yeast cell wall are now known. Importantly, the molecular composition and organization of the cell wall may vary considerably. For example, the incorporation of many cell wall proteins is temporally and spatially controlled and depends strongly on environmental conditions. Similarly, the formation of specific cell wall protein-polysaccharide complexes is strongly affected by external conditions. This points to a tight regulation of cell wall construction. Indeed, all five mitogen-activated protein kinase pathways in bakers' yeast affect the cell wall, and additional cell wall-related signaling routes have been identified. Finally, some potential targets for new antifungal compounds related to cell wall construction are discussed.