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The marine environment is an untapped source of bioactive compounds. Specifically, marine macroalgae (seaweeds) are rich in polysaccharides that could potentially be exploited as prebiotic functional ingredients for both human and animal health applications. Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth and/or activity of beneficial gut microbiota which, in turn, confer health benefits on the host. This review will introduce the concept and potential applications of prebiotics, followed by an outline of the chemistry of seaweed polysaccharides. Their potential for use as prebiotics for both humans and animals will be highlighted by reviewing data from both in vitro and in vivo studies conducted to date.
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... The dietary fiber laminarin is another storage carbohydrate of brown seaweed that comprises 1-25% of the dry weight, dependent on the harvesting time [4]. Laminarin is made of a β-(1,3) glucan with occasional β-(1,6) interchain links [6,7], which in its oligomeric or polymeric forms have potential biomedical applications [1]. Alginate, a structural carbohydrate, is available in the seaweed cell wall. ...
... For this purpose, seaweeds are of interest because of their significant number of bioactive compounds. Seaweed dietary fibers, including laminarin, alginate, and fucoidan, have prebiotic properties [7,12], meaning they can be utilized by the human gastrointestinal tract and some probiotic bacteria, providing health benefits for the host. ...
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The brown seaweed Alaria esculenta is the second most cultivated species in Europe, and it is therefore of interest to expand its application by developing food products. In this study, a lactic acid bacteria consortium (LAB consortium) consisting of three Lactiplantibacillus plantarum strains (relative abundance ~94%) and a minor amount of a Levilactobacillus brevis strain (relative abundance ~6%) was investigated for its ability to ferment carbohydrates available in brown seaweed. The consortium demonstrated the ability to ferment glucose, mannitol, galactose, mannose, and xylose, of which glucose and mannitol were the most favored substrates. No growth was observed on fucose, mannuronic and guluronic acid. The consortium used different pathways for carbohydrate utilization and produced lactic acid as the main metabolite. In glucose fermentation, only lactic acid was produced, but using mannitol as a carbohydrate source resulted in the co-production of lactic acid, ethanol, and succinate. Xylose fermentation resulted in acetate production. The consortium was also able to utilize laminari-oligosaccharides (DP2-4), obtained after enzymatic hydrolysis of laminarin, and produced lactic acid as a metabolite. The consortium could grow directly on A. esculenta, resulting in a pH decrease to 3.8 after 7 days of fermentation. Incubation of the same seaweed in corresponding conditions without inoculation resulted in spoilage of the seaweed by endogenous bacteria.
... The dietary fiber laminarin is another storage carbohydrate of brown seaweed that comprises 1-25% of the seaweed's dry weight, dependent on the harvesting time [4]. Laminarin is made of a β-(1,3) glucan with occasional β-(1,6) interchain links [6,7], which in its oligomeric or polymeric forms have potential biomedical applications [1]. Alginate, a structural carbohydrate, is available in the seaweed's cell wall. ...
... For this purpose, seaweeds are of interest because of their significant number of bioactive compounds. Seaweed dietary fibers, including laminarin, alginate, and fucoidan, have prebiotic properties [7,12], meaning they can be utilized by the human gastrointestinal tract and some probiotic bacteria, providing health benefits for the host. ...
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The brown seaweed Alaria esculenta is the second most cultivated species in Europe and it is therefore of interest to expand its application in developing food products. In this study, a lactic acid bacteria consortium (LAB consortium) consisting of three Lactiplantabacillus plantarum strains (relative abundance ~ 94%) and a minor amount of a Levilactobacillus brevis strain (relative abundance of ~ 6%) was investigated for its ability to ferment carbohydrates available in brown seaweed. The consortium demonstrated ability in fermenting glucose, mannitol, galactose, mannose, and xylose, of which glucose and mannitol were the most favored substrates; no growth was observed on fucose, mannuronic and guluronic acid. The consortium used different pathways for carbohydrate utilization and produced lactic acid as the main metabolite. In glucose fermentations, only lactic acid was produced, but use of mannitol as carbohydrate source, resulted in co-production of lactic acid, ethanol and succinate. Xylose fermentation resulted in acetate production. The consortium was also able to utilize laminari-oligosaccharides (DP 2-4), obtained after enzymatic hydrolysis of laminarin, and produced lactic acid as metabolite. The consortium could grow directly on A. esculenta, resulting in a pH decrease to 3.8 after 7 days of fermentation. Incubation of the same seaweed at corresponding conditions without inoculation resulted in spoilage of the seaweed by endogenous bacteria.
... Seaweed is rich in various bioactive compounds with anticancer, antioxidant, anti-inflammatory, and antibacterial properties [10][11][12]. More importantly, most of these active substances can resist gastric acid and host digestion, making seaweed a promising substrate for prebiotics [13]. Seaweed and its extracts can enhance nutrient digestibility and immune system function, thereby improving the growth and production performance of economic animals [14][15][16]. ...
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Kittens are prone to intestinal health problems as their intestines are not completely developed. Seaweed is rich in plant polysaccharides and bioactive substances that are highly beneficial to gut health. However, the effects of seaweed on cat gut health have not been assessed. This study compared the effects of dietary supplementation with enzymolysis seaweed powder and Saccharomyces boulardii on the intestinal health of kittens. In total, 30 Ragdoll kittens (age: 6 months; weight: 1.50 ± 0.29 kg) were assigned to three treatment groups for a 4-week feeding trial. The dietary treatment given was as follows: (1) basal diet (CON); (2) CON + enzymolysis seaweed powder (20 g/kg of feed) mixed evenly with the diet (SE); and (3) CON + Saccharomyces boulardii (2 × 1010 CFU/kg of feed) mixed evenly with the diet (SB). Compared with the CON and SB groups, dietary supplementation with the enzymolysis seaweed powder improved the immune and antioxidant capacity and also reduced the intestinal permeability and inflammation levels of kittens. The relative abundance of Bacteroidetes, Lachnospiraceae, Prevotellaceae, and Faecalibacterium in the SE group was higher than those in the CON and SB groups (p ≤ 0.05), while the relative abundance of Desulfobacterota, Sutterellaceae, and Erysipelatoclostridium in the SB group was lower than that in the SE group (p ≤ 0.05). Moreover, enzymolysis seaweed powder did not alter the level of intestinal SCFAs in kittens. Conclusively, supplementing kitten diet with enzymolysis seaweed powder can promote intestinal health by enhancing the gut barrier function and optimizing the microbiota composition. Our findings provide new perspectives on the application of enzymolysis seaweed powder.
... Macroalgae are taxonomically distributed in three major phyla: 1). Ochrophyta, commonly called brown algae because of their xanthophyll pigment "fucoxanthin"; 2) Chlorophyta, commonly called green algae because of their dominant chlorophyll pigments "a" and "b" and minor xanthophyll pigments; and 3) Rhodophyta, commonly called red algae because of their phycocyanin and phycoerythrin pigments (O'Sullivan et al., 2010). Traditionally, various species are discriminated based on their morphology; identification of macroalgae based on morphological characters is difficult because most genera are known for their diverse morphotypes (Méndez et al., 2019). ...
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Metal pollution in the marine coastal environment is an important topical issue. In this study, the water quality in five locations along the Alexandria coast (Eastern Harbor, El-Tabia pumping station, El Mex Bay, Sidi Bishir, and Abu Talat) was assessed by measuring physicochemical parameters from water samples. Depending on the morphological classification of macroalgae, the collected morphotypes were related to Ulva fasciata, Ulva compressa, Corallina officinalis, Corallina elongata, and Petrocladia capillaceae. Corallina officinalis and Corallina elongata demonstrated a high capacity for Cd, Pb, and Ni accumulation, and the highest values of Fe, Cu, and Mn were reported in Ulva fasciata and Ulva compressa. Two standard markers were applied, and results showed that the morphological classification matched the molecular data. Moreover, the analysis of algae can only reflect the accumulation of metals. The conclusion is that Ulva compressa and Corallina officinalis are potentially suitable indicators of localized short-term heavy metal pollution.
... Currently, the awareness in nutraceutical food products are growing due to their well-being beneficial properties. Consumer awareness is increasing regarding questions about food safety, namely food processing, storage, and additives source (O'Sullivan et al., 2010;. On a research and development level, their potential for the treatment of chronic diseases are explored on a large-scale basis (Choudhary and Grover, 2012;Ding et al., 2019). ...
... Brown seaweeds are rich in nondigestible polysaccharides, minerals, polyphenols and vitamins [9,10]. Wide-ranging biological activities [11] have been attributed to seaweed components, particularly fucoidan and laminarin, including prebiotic [12,13] and antibacterial [14,15] potential. However, various factors influence the concentration, structure and biological activity of seaweed-derived polysaccharides, such as seaweed species, harvest season, environmental conditions, and extraction methodologies [14,16]. ...
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Citation: Venardou, B.; O'Doherty, J.V.; Garcia-Vaquero, M.; Kiely, C.; Rajauria, G.; McDonnell, M.J.; Ryan, M.T.; Sweeney, T. In Vitro Evaluation of Brown Seaweed Laminaria spp. as a Source of Antibacterial and Prebiotic Extracts That Could Modulate the Gastrointestinal Microbiota of Weaned Pigs. Animals 2023, 13, 823. Simple Summary: The transition from milk to solid feed in commercial pig-production systems negatively affects gut health, particularly the composition of the residing microbial community. This can subsequently impair pig growth and long-term health. Natural dietary supplements including seaweed extracts have the capacity to reduce pathogen load (antibacterial activity) and/or increase beneficial microbes (prebiotic activity). This study evaluated the antibacterial and prebiotic potential of two seaweed species, Laminaria hyperborea and Laminaria digitata, and their extracts using laboratory-based simulations of the gut microbial community of weaned pigs. Our investigation identified seaweed extracts that could decrease the numbers of pig-and food-related pathogens or increase the number of beneficial microbes, albeit to a different extent. These findings indicate that seaweeds are a promising source of antibacterial and prebiotic dietary supplements for use in pigs during the weaning period. Abstract: Laminaria spp. and their extracts have preventative potential as dietary supplements during weaning in pigs. The first objective of this study was to evaluate increasing concentrations of four whole seaweed biomass samples from two different Laminaria species harvested in two different months in a weaned pig faecal batch fermentation assay. Particularly, February and November whole seaweed biomass samples of L. hyperborea (LHWB-F and LHWB-N) and L. digitata (LDWB-F and LDWB-N) were used. In the next part of the study, the increasing concentrations of four extracts produced from L. hyperborea (LHE1-4) and L. digitata (LDE1-4) were evaluated in individual pure-culture growth assays using a panel of beneficial and pathogenic bacterial strains (second objective). The LHE1-4 and LDE1-4 were obtained using different combinations of temperature, incubation time and volume of solvent within a hydrothermal-assisted extraction methodology (E1-4). In the batch fermentation assay, the L. hyperborea biomass samples, LHWB-F and LHWB-N, lowered Bifidobacterium spp. counts compared to the L. digitata biomass samples, LDWB-F and LDWB-N (p < 0.05). LHWB-F and LDWB-N reduced Enterobacteriaceae counts (p < 0.05). LHWB-F and LDWB-F were selected as the most and least promising sources of antibacterial extracts from which to produce LHE1-4 and LDE1-4. In the pure-culture growth assays, E1-and E4-produced extracts were predominantly associated with antibacterial and bifidogenic activities, respectively. LHE1 reduced both Salmonella Typhimurium and Enterotoxigenic Escherichia coli with LDE1 having a similar effect on both of these pathogenic strains, albeit to a lesser extent (p < 0.05). Both LHE1 and LDE1 reduced B. thermophilum counts (p < 0.05). LDE4 exhibited strong bifidogenic activity (p < 0.05), whereas LHE4 increased Bifidobacterium thermophilum and Lactiplantibacillus plantarum counts (p < 0.05). In conclusion, antibacterial and bifidogenic extracts of Laminaria spp. were identified in vitro with the potential to alleviate gastrointestinal dysbiosis in newly weaned pigs.
... Seaweed is rich in dietary fibre [34]. Dietary fibre content varies greatly between seaweed species (25-75% of dry weight) and is primarily soluble [35]. ...
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Seaweed is in the spotlight as a promising source of nutrition for humans as the search for sustainable food production systems continues. Seaweed has a well-documented rich nutritional profile containing compounds such as polyphenols, carotenoids and polysaccharides as well as proteins, fatty acids and minerals. Seaweed processing for the extraction of functional ingredients such as alginate, agar, and carrageenan is well-established. Novel pretreatments such as ultrasound assisted extraction or high-pressure processing can be incorporated to more efficiently extract these targeted ingredients. The scope of products that can be created using seaweed are wide ranging: from bread and noodles to yoghurt and milk and even as an ingredient to enhance the nutritional profile and stability of meat products. There are opportunities for food producers in this area to develop novel food products using seaweed. This review paper discusses the unique properties of seaweed as a food, the processes involved in seaweed aquaculture, and the products that can be developed from this marine biomass. Challenges facing the industry such as consumer hesitation around seaweed products, the safety of seaweed, and processing hurdles will also be discussed.
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A total of 154 strains from 22 species of Bifidobacterium, Peptostreptococcus, Lactobacillus, Ruminococcus, Coprococcus, Eubacterium, and Fusobacterium, which are present in high concentrations in the human colon, were surveyed for their ability to ferment 21 different complex carbohydrates. Plant polysaccharides, including amylose, amylopectin, pectin, polygalacturonate, xylan, laminarin, guar gum, locust bean gum, gum ghatti, gum arabic, and gum tragacanth, were fermented by some strains from Bifidobacterium, Peptostreptococcus, Ruminococcus, and Eubacterium species. Porcine gastric mucin, which was fermented by some strains of Ruminococcus torques and Bifidobacterium bifidum, was the only mucin utilized by any of the strains tested.
Chapter
In 1995, Gibson and Roberfroid defined a prebiotic as a “nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limitednumber of bacteria in the colon, and thus improves host health.” This definition only considers microbial changes in the human colonic ecosystem. Later, itwas considered timely to extrapolate this into other areas that may benefit from a selective targeting of particular microorganisms and to propose a refined definition of a prebiotic as (Gibson et al. 2004): a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinalmicrofiora that confers benefits.
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Two experiments were conducted to evaluate the effect of administration of fructooligosaccharides (FOS) and Bifidobacterium longum on growth performance and fecal bacterial populations in pigs weaned at 18 d of age. In exp. 1, two groups of 20 pigs each were fed diets containing 0 or 0.5% FOS for 21 d. On days 1 and 3, pigs receiving FOS were administered an oral dose of 10(10) B. longum cells. During week 1, average daily gain was higher and feed efficiency was improved (P < 0.05) in pigs fed FOS and bifidobacteria relative to the control. On day 7, supplemented pigs had reduced numbers of total anaerobes and clostridia, and increased numbers of bifidobacteria in faeces (P < 0.05). in exp. 2, 80 pigs were divided into four groups of 20 animals each in a 2 x 2 factorial design. Main effects included FOS supplementation (0 or 0.5% of diet) and B. longum supple mentation (0 or 10(7) cells per gram feed). FOS supplementation reduced growth while B. longum supplementation increased growth (P < 0.05). On days 12 and 19, serum insulin-like growth factor I (IGF-I) was reduced with FOS supplementation and increased with B. longum supplementation (P < 0.05). It was concluded that the continuous administration of bifidobacteria provided a beneficial effect on growth parameters studied in this experiment.
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The inhibitory effects of laminaran and low molecular weight sodium alginate (MW = 49,000) against formation of ammonia, indole compounds and phenol compounds, putrefactive and harmful compounds, induced by human fecal microflora, were examined in vitro. Laminaran was fermented to acetate, propionate, n-butyrate and lactate. The alginate was fermented to acetate and propionate. Both of these polysaccharides inhibited formation of the putrefactive compounds. In the case of rats fed diet containing 2% (w/w) laminaran or low molecular alginate, the fermentation pattern agreed with that of the in vitro experiment. Laminaran suppressed indole, p-cresole and sulfide, significantly. These putrefactive compounds, in rats fed low molecular alginate, also tended to be lower. These results suggest that the fermentation of laminaran by intestinal bacteria suppresses the putative risk markers for colon cancer.
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Algal polysaccharides are indigestible and exhibit unusual biochemical and fermentative characteristics from which stem interesting biological effects such as antitumoral, immunostimulating and/or prebiotic effects. In this study, we aimed to determine whether oligosaccharides obtained from alginates and laminarans also have such biological activities and can thus be considered as functional foods. The chemical structures of the oligosaccharides were determined using NMR. Both the fermentation and the effects on microbial populations of oligo-alginates and oligo-laminarans were investigated using batch incubations with, and continuous culture of, human faecal bacteria. The kinetic and intensity of fermentation were measured by continuous monitoring of gas production and determination of final pH value, respectively. Effects on intestinal flora activity and composition were determined via metabolite quantification and main bacterial genera enumeration. Cytotoxic, proliferative and differentiating effects were estimated after exposure of epithelial (Caco-2), monocytic (THP1) and lymphocytic T (Jurkat) cell lines. Despite very different biochemical structures, the two oligo-alginates exhibited similar fermentation patterns. As with native alginates, they required adaptation prior to their metabolism. However, this adaptation did not result in any change in the global bacterial composition. No noticeable biological effect was detected for oligo-alginates, In contrast to native laminarans, oligo-laminarans did not require adaptation prior to their fermentation. Propionate production was stimulated but no significant modification of the balance between the main bacterial genera was observed during continuous culture of human fecal flora. Oligo-laminarans exhibited slightly inhibitory effects on Caco-2 cells, inhibited mononuclear cell proliferation and stimulated the expression of ICAM-1 by monocytic cells. This last property appears promising, and may allow algal oligosides to be used as functional foods and/or components.