Article

Effects of Konjac glucomannan hydrolysates on the gut microflora of mice

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  • Glycologic Limited
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Abstract

Purpose – The aim of this study is to determine the effects of depolymerised mannans and specifically konjac glucomannan hydrolysates (GMH) on the colonic microflora of mice. Blood glucose and cholesterol were also measured. Design/methodology/approach – Two groups (n = 20) of 12‐week old Wister mice were used for a period of 14 weeks. One group (treatment group) were fed diets containing 5 per cent konjac GMH dissolved in drinking water in addition to the control (group) standard diet. Faecal microflora, feed consumption, body weight, blood glucose and cholesterol were determined. Findings – The GMH promoted the growth of anaerobes and lactobacilli in the treatment group where this was statistically, highly significant (P < 0.001). Also, the hydrolysate was able to reduce highly significantly (P < 0.001) faecal Clostridium perfringens and Escherichia coli counts. A significant increase in average daily feed consumption (P < 0.05) and weekly body weight (P < 0.001) was found for the treatment group. The mean ± SD (mmol/l) of blood glucose and cholesterol was lower in the treatment group. Originality/value – In addition to modulating the gut microflora, GMH seems to lower the blood glucose and cholesterol in mice. Although this needs to be verified by further studies, GMH could also be a candidate for possible treatment of subjects with high cholesterol and for diabetics.

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... Zouboulis et al. [3] reported that pro-inflammatory lipids and chemokines/cytokines seem to act as mediators for the initiation of acne lesions, although they reported that Propionibacterium acnes is not involved initially in the lesions but may mediate later inflammatory events leading to worsening of the condition. Prebiotics in general and glucomannans in particular have been found to stimulate the immune system in vitro and in vivo [4][5][6][7][8]. Glucomannan hydrolysates stimulate the growth of probiotic microorganisms such as lactic acid bacteria (LAB) but inhibit the growth of undesirable ones [4]. ...
... Here, the glucomannan hydrolysate stimulated the growth of LAB strains which inhibited the bacterium. It has been well demonstrated in the literature that lactic acid bacteria inhibit the growth of pathogens by various mechanisms including the production of acids, H 2 O 2 and bacteriocins [10][11][12][13][14]. Lactic acid bacteria growth on prebiotics and associated depression of pathogen growth has been shown for staphylococci and salmonellae [15] and for Listeria monocytogens, Clostridium perfringens and E. coli (in the presence of glucomannan hydrolysates) [4,5]. The mean ± standard deviation (duplicate) of the diameter of inhibition zone of Propionibacterium acnes by LAB and/or GMH on agar plates using pour plate ( Fig. 1) or spread plate ( Fig. 2) methods was recorded. ...
... The inhibition zone method was chosen because the well or disc diffusion techniques are widely used in vitro to determine the antimicrobial inhibitory effect profiles [16,17]. Konjac glucomannan hydrolysates have the potential use as a prebiotic [4] and stimulate the growth of probiotic micro-organisms including lactobacilli [5]. It is assumed, based on the previous work by these authors [4], that the micro-organisms prefer the mannose : glucose substrate (1.6 : 1) such as found in konjac hydrolysates [18], because of (i) the nature of the sugars and (ii) the accessibility of these sugars as carbon sources. ...
Article
The synbiotic ability of probiotic bacteria and konjac glucomannan hydrolysates (GMH) to inhibit acne-inducing bacterium, Propionibacterium acnes growth was studied in vitro. All probiotic bacteria strains tested were able to inhibit the growth of this species of skin bacterium where the inhibition was significantly (P < 0.01) enhanced by the presence of the GMH prebiotic. As the current treatment of acne is based on topical or systemic drugs, it is worth examining further the biotherapeutic activities of the GMH and selected probiotics with a view to future use as prophylactic or therapeutic synbiotics for treating acne infections.
... Prebiotics represent dietary fibre/dietary fibre residues which find their way to the colon and provide a carbon source for probiotic " healthy " bacteria growth. Prebiotics in general and glucomannans in particular, have been found to stimulate the colonic health bacteria and the immune system (Al-Ghazzewi et al., 2007; Elamir et al., 2008; Torrecillas et al., 2007). In the present study, the synbiotic effects of hydrolysed konjac glucomannan and lactobacilli on the growth of S. aureus and S. typhimurium was examined in vitro. ...
... It has been well demonstrated in the literature that lactic acid bacteria inhibit the growth of pathogens including S. aureus (Gan et al., 2002), Propionibacterium acnes and Staphylococcus epidermidis (Kang et al., 2009) by various mechanisms – including the production of acids, hydrogen peroxide and bacteriocins (Bevilacqua et al., 2003; Cheekily and Saris, 2003; Santos et al., 2003). Lactic acid bacteria growth on prebiotics and associated depression of pathogen growth has been shown for staphylococci and salmonellae (Gilliland and Speck, 1972) and for Listeria monocytogens, C. perfringens and Escherichia coli in the presence of GMH (Al-Ghazzewi et al., 2007; Elamir et al., 2008). Kitamoto et al. (2003) studied the bactericidal effects of konjac " fluid " (solubilised extract) on several food-poisoning bacteria. ...
... Kitamoto and co-workers also found konjac " fluid " was effective in reducing of spore-forming bacteria (Bacillus subtilis, Bacillus cereus, C. perfringens, and Clostridium botulinum type E and A). The GMH has the potential to be used as a prebiotic (Al-Ghazzewi et al., 2007) and stimulate the growth of probiotic microorganisms including lactobacilli (Elamir et al., 2008). The lactic acid bacteria prefer the mannose:glucose substrate ratio (1.6:1) such as found in konjac glucomannan (Khanna, 2003), because of: . ...
Article
Purpose – The purpose of this paper is to investigate how synbiotic combinations of lactobacilli with konjac glucomannan hydrolysate (GMH) may be used to reduce Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium) growth in vitro. Design/methodology/approach – Growth of S. aureus and S. typhimurium was assessed individually and when mixed with L. acidophilus in modified media supplemented with two per cent GMH. The effect of the GMH and the Lactobacillus strain on S. aureus growth was also investigated using the well diffusion test on Muller‐Hinton agar medium. Findings – The results showed that L. acidophilus “out grew” the pathogens S. aureus and S. typhimurium in the presence of konjac glucomannan in the mixed cultures. Originality/value – The paper demonstrates that konjac glucomannan hydrolysates combined with probiotic bacteria, may be used to inhibit the growth of pathogenic bacteria such as S. aureus and S. typhimurium. These data support the development of an alternative approach to reduce infections and promote consumer health.
... KGM has recently been marketed in capsule form, as a drink mix and in food products (Brown, 2000;Talbott, 2003) and has been touted for its potential in the treatment of obesity (Kraemer et al., 2007), obesity-related dyslipidemia (Gallaher et al., 2000;Keithley and Swanson, 2005;Vasques et al., 2008) and diabetes (Vuksan et al., 1999(Vuksan et al., , 2000(Vuksan et al., , 2001 by promotion of satiety (Sood et al., 2008). The potential use of KGM as a prebiotic (Al-Ghazzewi et al., 2007;Chen et al., 2005Chen et al., , 2006Chen et al., , 2008Elamir et al., 2008;Wang et al., 2008) and as an immunomodulator (Onishi et al., 2007a,b) has also been suggested. ...
... These data suggest that supplementing the diet with 5% (w/w) KGM or KGMO for 4 weeks is sufficient to enhance the population of Bifidobacteria, associated with decreased C. perfringens and Escherichia coli. Similar observations have been reported by Elamir et al. (2008) in a study on the effects of KGMO on the gut microflora of mice. They reported that the KGMO was able to significantly reduce faecal C. perfringens and E. coli counts. ...
... This can be either due to the action of Bifidobacteria through the increase in acidic fermentation products (mainly acetate and lactose) and secretion of anti-microbial substances, or might due to the anti-microbial properties of KGM. The latter has been demonstrated by an in vitro study showing that KGM and KGM hydrolysate prevent the growth of food-borne C. perfringens and E. coli (Al-Ghazzewi et al., 2007;Elamir et al., 2008). In addition, increased SCFA concentration and decreased faecal pH observed in treated subjects for both studies also indicated that the promotion of colonic fermentation had taken place. ...
Article
Amorphophallus konjac (konjac) has long been used in China, Japan and South East Asia as a food source and as a traditional medicine. Flour extracted from the corm of this species is used in Far Eastern cuisine to make noodles, tofu and snacks. In traditional Chinese medicine (TCM), a gel prepared from the flour has been used for detoxification, tumour-suppression, blood stasis alleviation and phlegm liquefaction; and for more than 2000 years has been consumed by the indigenous people of China for the treatment of asthma, cough, hernia, breast pain, burns as well as haematological and skin disorders.
... KGM has recently been marketed in capsule form, as a drink mix and in food products (Brown, 2000;Talbott, 2003) and has been touted for its potential in the treatment of obesity (Kraemer et al., 2007), obesity-related dyslipidemia (Gallaher et al., 2000;Keithley and Swanson, 2005;Vasques et al., 2008) and diabetes (Vuksan et al., 1999(Vuksan et al., , 2000(Vuksan et al., , 2001 by promotion of satiety (Sood et al., 2008). The potential use of KGM as a prebiotic (Al-Ghazzewi et al., 2007;Chen et al., 2005Chen et al., , 2006Chen et al., , 2008Elamir et al., 2008;Wang et al., 2008) and as an immunomodulator (Onishi et al., 2007a,b) has also been suggested. ...
... These data suggest that supplementing the diet with 5% (w/w) KGM or KGMO for 4 weeks is sufficient to enhance the population of Bifidobacteria, associated with decreased C. perfringens and Escherichia coli. Similar observations have been reported by Elamir et al. (2008) in a study on the effects of KGMO on the gut microflora of mice. They reported that the KGMO was able to significantly reduce faecal C. perfringens and E. coli counts. ...
... This can be either due to the action of Bifidobacteria through the increase in acidic fermentation products (mainly acetate and lactose) and secretion of anti-microbial substances, or might due to the anti-microbial properties of KGM. The latter has been demonstrated by an in vitro study showing that KGM and KGM hydrolysate prevent the growth of food-borne C. perfringens and E. coli (Al-Ghazzewi et al., 2007;Elamir et al., 2008). In addition, increased SCFA concentration and decreased faecal pH observed in treated subjects for both studies also indicated that the promotion of colonic fermentation had taken place. ...
Article
Kudzu root (Gegen in Chinese) is the dried root of Pueraria lobata (Willd.) Ohwi, a semi-woody, perennial and leguminous vine native to South East Asia. It is often used interchangeably in traditional Chinese medicine with thomson kudzu root (Fengen in Chinese), the dried root of P. thomsonii, although the Chinese Pharmacopoeia has separated them into two monographs since the 2005 edition. For more than 2000 years, kudzu root has been used as a herbal medicine for the treatment of fever, acute dysentery, diarrhoea, diabetes and cardiovascular diseases. Both English and Chinese literatures on the traditional applications, phytochemistry, pharmacological activities, toxicology, quality control and potential interactions with conventional drugs of both species have been included in the present review. Over seventy phytochemicals have been identified in kudzu root, with isoflavonoids and triterpenoids as the major constituents. Isoflavonoids, in particular puerarin, have been used in most of the pharmacological studies. Animal and cellular studies have provided support for the traditional uses of kudzu root on cardiovascular, cerebrovascular and endocrine systems, including diabetes and its complications. Further studies to define the active phytochemical compositions, quality standards and clinical efficacy are warranted. Strong interdisciplinary collaboration to bridge the gap between traditional medicine and modern biomedical medicine is therefore needed for the development of kudzu root as an effective medicine for the management of diabetes and cardiovascular diseases.
... Prebiotics in general and glucomannans in particular have been found to stimulate the immune system in vitro and in vivo (Swanson et al., 2002; Yamada et al., 2003; Al-Ghazzewi et al., 2007; Torrecillas et al., 2007; Elamir et al., 2008). Glucomannan hydrolysate (GMH) stimulates the growth of probiotic micro organisms such as lactic acid bacteria (LAB) but inhibits the growth of undesirable bacteria in mixed cultures (Al-Ghazzewi et al., 2007). ...
... Glucomannan hydrolysate (GMH) stimulates the growth of probiotic micro organisms such as lactic acid bacteria (LAB) but inhibits the growth of undesirable bacteria in mixed cultures (Al-Ghazzewi et al., 2007). Fermentation of prebiotic carbohydrates by the acidogenic LAB result in low pH and subsequently contribute towards inhibiting the growth of the obligate anaerobes (Gibson et al., 1995; Burton et al., 2006; Al-Ghazzewi et al., 2007; Elamir et al., 2008). Of these, a number of Streptococcus species colonise the oral cavity (Kazor et al., 2003). ...
... The current issue and full text archive of this journal is available at www.emeraldinsight.com/0034-6659.htm NFS 41,4 Both in vitro and in vivo evidence has shown that GMH can promote the health of digestive system (Chen et al., 2005; Al-Ghazzewi et al., 2007; Elamir et al., 2008), vaginal thrush (Sutherland et al., 2008 ), skin diseases (Ghazzewi and Tester, 2010) and wound healing (Tizard et al., 1989). Glucomannans, promote the growth, metabolism and antimicrobial properties of probiotic micro organisms (Al-Ghazzewi et al., 2007) – supporting the potential application of GMH for oral hygiene. ...
Article
Purpose – The purpose of this paper is to determine the effect of synbiotic combination of lactobacilli with konjac glucomannan hydrolysate (GMH) to reduce Streptococcus mutans growth in vitro with the intention of characterising its efficacy as a new approach for oral hygiene. Design/methodology/approach – Strains of Lactobacillus acidophilus and S. mutans were grown individually or in combination in modified Columbia base broth supplemented with 2 per cent GMH. Following incubation, the samples were plated on De Man, Rogosa and Sharpe and Columbia blood agar and growth of both strains was assessed. Findings – The probiotic bacteria L. acidophilus was able to “out grow” S. mutans in the presence of konjac glucomannan in the mixed cultures. Originality/value – The results indicate that consumption of prebiotic and probiotic combinations may play a role as potential prophylactic or therapeutic agents for reducing the presence of organisms in the mouth associated with tooth decay. In order to confirm a beneficial effect of GMH further in vivo in this concept, studies involving healthy human volunteers should be considered.
... KGM has recently been marketed in capsule form, as a drink mix and in food products (Brown, 2000; Talbott, 2003) and has been touted for its potential in the treatment of obesity (Kraemer et al., 2007), obesity-related dyslipidemia (Gallaher et al., 2000; Keithley and Swanson, 2005; Vasques et al., 2008) and diabetes (Vuksan et al., 1999Vuksan et al., , 2000Vuksan et al., , 2001) by promotion of satiety (Sood et al., 2008). The potential use of KGM as a prebiotic (Al-Ghazzewi et al., 2007; Chen et al., 2005 Chen et al., , 2006 Chen et al., , 2008 Elamir et al., 2008; Wang et al., 2008) and as an immunomodulator (Onishi et al., 2007a,b) has also been suggested. The unique rheological and gelling properties of KGM are widely employed in emulsifier and stabiliser products for the food, drinks, cosmetic and pharmaceutical industries. ...
... These data suggest that supplementing the diet with 5% (w/w) KGM or KGMO for 4 weeks is sufficient to enhance the population of Bifidobacteria, associated with decreased C. perfringens and Escherichia coli. Similar observations have been reported by Elamir et al. (2008) in a study on the effects of KGMO on the gut microflora of mice. They reported that the KGMO was able to significantly reduce faecal C. perfringens and E. coli counts. ...
... This can be either due to the action of Bifidobacteria through the increase in acidic fermentation products (mainly acetate and lactose) and secretion of anti-microbial substances, or might due to the anti-microbial properties of KGM. The latter has been demonstrated by an in vitro study showing that KGM and KGM hydrolysate prevent the growth of food-borne C. perfringens and E. coli (Al-Ghazzewi et al., 2007; Elamir et al., 2008). In addition, increased SCFA concentration and decreased faecal pH observed in treated subjects for both studies also indicated that the promotion of colonic fermentation had taken place. ...
... a not determined. Khanna, Tester, & Piggott, 2007;Connolly, Lovegrove, & Tuohy, 2010;Elamir et al., 2008), restricting the growth of pathogens in the gut and associated toxicity ( Azezli, Bayraktaroglu, & Orhan, 2007;Banlunara, Bintvihok, & Kumagai, 2005;Kitamoto et al., 2003;Madrigal-Santillan, Alvarez-Conzalez, Marquez-Marquez, Velázquez-Guadarrama, & Madrigal-Bujaidar, 2007;Wang, Lai, Chen, & Chen, 2008;Ye, Lin, & Chen, 2010), cholesterol binding ( Arvill & Bodin, 1995;Chen, Fan, Chen, & Chan, 2005;Chen, Sheu, Tai, Liaw, & Chen, 2003;Elamir et al., 2008;Gallaher et al., 2002;Livieri et al., 1992;Vuksan et al., 2000;Walsh et al., 1984;Yang et al., 2001) and control of glucose absorption (diabetes role) ( Chen et al., 2003;Huang et al., 1990;Melga, Giusto, Ciuchi, Giusti, & Prando, 1992;Vuksan et al., 2000;Vuksan et al., 2001). Extensively depolymerised konjac glucomannan molecules, unlike the native (highly swelling) forms, do not appear to promote weight reduction and calorie control ( Smith et al., 2010). ...
... a not determined. Khanna, Tester, & Piggott, 2007;Connolly, Lovegrove, & Tuohy, 2010;Elamir et al., 2008), restricting the growth of pathogens in the gut and associated toxicity ( Azezli, Bayraktaroglu, & Orhan, 2007;Banlunara, Bintvihok, & Kumagai, 2005;Kitamoto et al., 2003;Madrigal-Santillan, Alvarez-Conzalez, Marquez-Marquez, Velázquez-Guadarrama, & Madrigal-Bujaidar, 2007;Wang, Lai, Chen, & Chen, 2008;Ye, Lin, & Chen, 2010), cholesterol binding ( Arvill & Bodin, 1995;Chen, Fan, Chen, & Chan, 2005;Chen, Sheu, Tai, Liaw, & Chen, 2003;Elamir et al., 2008;Gallaher et al., 2002;Livieri et al., 1992;Vuksan et al., 2000;Walsh et al., 1984;Yang et al., 2001) and control of glucose absorption (diabetes role) ( Chen et al., 2003;Huang et al., 1990;Melga, Giusto, Ciuchi, Giusti, & Prando, 1992;Vuksan et al., 2000;Vuksan et al., 2001). Extensively depolymerised konjac glucomannan molecules, unlike the native (highly swelling) forms, do not appear to promote weight reduction and calorie control ( Smith et al., 2010). ...
... Their elegant work profiled the hydrolysates produced from konjac glucomannan by these two enzyme systems and related the product structures/distribution to their in vitro fermentability. Hydrolysed konjac glucomannan is an effective prebiotic in mice ( Elamir et al., 2008;Pan, Chen, Wu, Tang, & Zhao, 2009); in fact a more effective prebiotic than native konjac glucomannan ( Chen et al., 2005). Fermentation of konjac glucomannan and hydrolysed konjac glucomannan may protect against oxidative stress in the human colon ( Wang et al., 2008). ...
... A validated claim for glucomannan with respect to regulating blood cholesterol concentrations has already been agreed by the European Food Standards Association and the European Food Safety Authority (EFSA, 2010). Not only does native glucomannan have an effect on blood glucose and blood lipid, depolymerised konjac glucomannan has also been reported to lower cholesterol and blood glucose in mice (Elamir et al., 2008). Studies on humans using the depolymerised material have been conducted by Suwannaporn, Tester, Al- Ghazzewi, and Artitdit (2015). ...
... The authors reported that the hydrolysates acted as prebiotics by producing selective stimulation of beneficial gut microbiota and a favourable short chain fatty acid (SCFA) profile. This outcome was in agreement with Ghazzewi et al. (2007) and Elamir et al. (2008). In human trials, Huang et al. (2007) reported that konjac glucomannan hydrolysates promote the growth (selectively) of colonic probiotic bacteria (both lactobacilli and bifidobacteria). ...
... Mannan-oligosaccharides have been reported to increase colonic bifidobacteria but decrease faecal E. coli in dogs (Grieshop et al., 2004 ). Furthermore, depolymerised glucomannans stimulate the growth of beneficial bacteria at the expense of pathogen such as Salmonella typhimurium, Clostridium perfringens, Listeria monocytogenes, E. coli, Staphylococcus aureus and Propionibacterium acnes (Ghazzewi & Tester, 2010; Al-Ghazzewi, Tester, & Alvani, 2012; Al-Ghazzewi et al., 2007; Elamir et al., 2008). Connolly et al. (2010) compared depolymerised konjac glucomannans with inulin for modulating human faecal bacterial composition. ...
Article
The roles of native and depolymerised glucomannans in the diet are reviewed together with their impact in health and disease. The structure and properties of the carbohydrates are also considered together with their roles as microbiological substrates and their interactions with non-pathogens and pathogens. Native glucomannans have been consumed for centuries in Asia within food products and are permitted food thickeners through the world. However, their strong gel structures limit applications in the diet. Depolymerised and native glucomannans are considered therefore in this review with relevant dietary applications. These applications include swallowing (dysphagia), nutrient absorption control, satiety, dietary-fibre, inflammatory bowel disease, colonic benefits (such as prebiotic).
... Konjac glucomannan is used as a gelling agent, thickener, emulsifier and stabiliser in foods (Imeson, 2009). Interestingly, it has a number of desirable nutritional characteristics which include: providing dietary fibre (Chiu & Stewart, 2012); as an aid to avoid constipation (Chen et al., 2008); a laxative (Chen, Cheng, Liu, Liu, & Wu, 2006); help with the management of diverticulitis (Latella et al. 2003;Frieri, Pimpo, & Scarpignato, 2006;Petruzziello, Iacopini, Bulajic, Shah, & Costamagna, 2006); satiety (Keithley & Swanson, 2005); a fermentable substrate (Chen, Fan, Chen, & Chan, 2005) in the colon (prebiotic); restricting the growth of pathogens in the gut (Elamir et al., 2008) plus; control of cholesterol and glucose absorption (Arvill & Bodin, 1995;Gallaher et al., 2002;Sood, Baker, & Coleman, 2008). ...
... It has been reported that both native and hydrolysed konjac glucomannans have positive health benefits in the gut (Elamir et al., 2008;Pan, Chen, Wu, Tang, & Zhao, 2009;Tester, & Al-Ghazzewi, 2009. Chen et al., (2008) reported that native konjac flour can promote bowel movement by thirty percent and improve colonic ecology in constipated adults. ...
Article
Carbohydrates may provide an alternative therapeutic approach for a number of digestive health disorders such as inflammatory bowel disease (IBD). The aim of this work was to characterise the tolerance and efficacy of low and high molecular weight konjac glucomannan hydrolysates within healthy volunteers and patients suffering from IBD and associated gut conditions. These conditions included constipation, Crohn's disease and ulcerative colitis. For general tolerance, fourteen patients participated whilst for the digestive disorder trial, there were twenty. Scores of taste/texture of the product, bowel movement, stool consistency, diarrhoea, existence/absence of blood in the faeces, abdominal pains, flatulence, vomiting, fever, improvement of life style after use, willingness to use in the future and clinician's statements about each patient's conditions before and after use were recorded. The results showed that the hydrolysates were tolerated well for patients with diarrhoea and had a significant improvement on bowel movement, stool consistency, abdominal pain and flatulence after ten days. With respect to effects on IBD, there was a significant health benefit after fourteen days of consumption for bowel movement, stool consistency, diarrhoea, existence/absence of blood in the faeces, abdominal pain, flatulence and vomiting. Most patients declared an improvement of their life style after consuming the hydrolysates. The use of konjac glucomannan hydrolysates as a therapeutic agent or adjunct to standard treatments could prove a successful tool for the treatment of a range of disorders; although large scale studies are required to characterise further the role of the carbohydrates.
... Prebiotics in general and gluco mannans in particular have been found to stimulate the immune system in vitro and in vivo [11,12,13,14,15]. Akiyama et al [16] reported that gluco-oligosaccharides can be used to control the growth of Staphylococcus aureus. ...
... Akiyama et al [16] reported that gluco-oligosaccharides can be used to control the growth of Staphylococcus aureus. More recently, it was found that konjac gluco mannan hydrolysates (GMH) can stimulate the gro wth of probiotic microorganis ms such as lactic acid bacteria (LA B) but inh ibit the growth of undesirable ones such as Escherichia coli, Clostridium perfringens, Listeria monocytogens [11,12], and Propionibacterium acnes [17]. Lactobacilli use different mechanis ms to inhibit the growth of pathogens such as lowering p H (producing acids), excreting natural antibiotics, blocking pathogen adhesion and or co mpetition for nutrients [18]. ...
Article
Konjac glucomannan hydrolysate was derived enzymatically from konjac flour under optimal conditions. A number of culture strains of lactobacilli and bifidobacteria were grown on De Man, Rogosa and Sharpe (MRS) media supplemented with the hydrolysate. This hydrolysate stimulated the growth of all strains examined. Colony sizes of those strains grown on konjac hydrolysate were significantly (P = 0.001) bigger than those grown on pectin or xylan hydrolysates. Bacterial growth profiles were also conducted on nutrient agar (MRS or modified MRS agar containing konjac hydrolysate) using single strains of lactobacilli or bifidobacteria (Lactobacillus acidophilus, Lactobacillus casei or Bifidobacterium adolescentis), single pathogen cultures (Escherichia coli or Listeria monocytogenes) or mixed bacterial cultures (from chicken breast extract). Although the growth of lactobacilli inhibited the growth of pathogens (single or mixed culture) the pathogens could not grow on the konjac hydrolysate as a sole carbon source. Microbial growth profiles using konjac hydrolysate or inulin in UHT milk were also investigated. The results showed that the numbers of colony forming units (cfu) obtained from milk containing the konjac hydrolysate were significantly (P = 0.01) higher than those containing inulin. It is suggested that the unique properties of konjac hydrolysate make it universally valuable as a prebiotic which can be applied to a wide range of foods, feeds and healthcare/pharmaceutical products. Copyright © 2007 Society of Chemical Industry
... Test groups had one ear punched where a 1.0 mm diameter punch hole was created in one ear using a thumb type punch (Model 4.7.3, 340138, Harvard Apparatus Ltd., Edenbridge, Kent, UK). In addition, one control and one test group were fed the konjac GMH dissolved in the drinking water at 5% (w/v) (Chen, Fan, Chen, & Chan, 2005; Elamir et al., 2008) after the adaptation period. All groups were 'fed rat and mouse standard diet' from 'BEEKAY' (Bantin and Kingman Ltd., Hull, UK). ...
... Test groups had one ear punched where a 1.0 mm diameter punch hole was created in one ear using a thumb type punch (Model 4.7.3, 340138, Harvard Apparatus Ltd., Edenbridge, Kent, UK). In addition, one control and one test group were fed the konjac GMH dissolved in the drinking water at 5% (w/v) ( Chen, Fan, Chen, & Chan, 2005;Elamir et al., 2008) after the adaptation period. All groups were 'fed rat and mouse standard diet' from 'BEEKAY' (Bantin and Kingman Ltd., Hull, UK). ...
Article
The objective of this work was to determine the effects of ingested depolymerised glucomannans on wound healing. Mice were divided into four groups of twenty each: control - drinking water; control - drinking water containing 5% (w/v) glucomannan hydrolysate (GMH); test - drinking water with punched ear and; test - drinking water containing 5% (w/v) GMH with punched ear. Healing scores were recorded over eight days while body weight was taken four times over the trial period. There was faster healing for the group drinking water containing GMH. The consumption of hydrolysed glucomannan may encourage wound healing due to a number of immunosupportive effects.
... Prebiotics in general and gluco mannans in particular have been found to stimulate the immune system in vitro and in vivo [11,12,13,14,15]. Akiyama et al [16] reported that gluco-oligosaccharides can be used to control the growth of Staphylococcus aureus. ...
... Akiyama et al [16] reported that gluco-oligosaccharides can be used to control the growth of Staphylococcus aureus. More recently, it was found that konjac gluco mannan hydrolysates (GMH) can stimulate the gro wth of probiotic microorganis ms such as lactic acid bacteria (LA B) but inh ibit the growth of undesirable ones such as Escherichia coli, Clostridium perfringens, Listeria monocytogens [11,12], and Propionibacterium acnes [17]. Lactobacilli use different mechanis ms to inhibit the growth of pathogens such as lowering p H (producing acids), excreting natural antibiotics, blocking pathogen adhesion and or co mpetition for nutrients [18]. ...
... In addition, the number of colony-forming units (CFU) in milk supplemented with HKGM was higher than in those supplemented with inulin. A similar result was also reported by Elamir et al. (2008). Elamir and co-workers investigated the effects of depolymerised mannans and specifically HKGM on the colonic microflora of mice. ...
Article
Konjac glucomannan (KGM) and hydrolysed konjac glucomannan (HKGM) are natural polysaccharides that have many applications in the food and non-food fields (chemical and health industries) due to their non-hazardous, non-toxic, biocompatible properties and good solubility. KGM was produced from pulverising chips, followed by air classification of solid particles to separate them from impurities or ethanol precipitation. Production of KGM from the genus Amorphophallus by the extraction and purification methods was critically reviewed. Characteristics of the physicochemical properties of KGM were outlined, and the preparation of HKGM was also discussed. The potential of KGM and HKGM to provide health benefits, such as being prebiotics or anti-inflammatory and antitumour agents, were considered. A brief discussion on the safe usage of KGM and HKGM is included. Meanwhile, HKGM was prepared by physical-acid treatments or enzymic degradation. Clinical studies have demonstrated that supplementing the diet with KGM or HKGM significantly lowers plasma glucose and reduces inflammation in rat models. Tumour was reduced when KGM was added to the test meals.
... Glucomannans are a subclass of mannans (Schröder et al., 2009) mainly comprising mannose and glucose sugars with desirable nutritional and health characteristics, such as dietary fiber (Chen et al., 2008). In addition, glucomannan is a prebiotic ingredient, which can stimulate the growth of Lactobacillus and Bifidobacterium, suppress pathogenic bacterial growth, and increase the production of shortchain fatty acids (Chen et al., 2005;Elamir et al., 2008;Connolly et al., 2010). Mannan oligosaccharides directly affect broilers gut health by improving the integrity of the intestinal mucosa, attaching to E. coli and Salmonella, and preventing these pathogens from infiltrating the intestinal wall (Manafi et al., 2016). ...
Article
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Antibiotic growth promoters have been widely used in poultry to improve overall performance. The emergence of antibiotic resistance has resulted in sanctions imposed on the use of antibiotics in poultry diets, and alternatives such as herbal extracts are being considered to improve growth performance. The aim of this study was to compare the performance and feed digestibility of the feed supplement Novacid, which contains organic acids, glucomannan, and phytochemicals, with that of the antibiotic growth promoter bacitracin methylene disalicylate (BMD) in commercial broiler chickens. Six hundred 1-d-old Ross × Ross 308 male broiler chicks were randomly and equally assigned to six treatment groups with five replicates each (20 chicks per replicate). The chicks were fed a corn–soybean meal basal diet, and divided into two groups: unchallenged and challenged with E. coli (400 mg/kg Escherichia coli inoculation). Each of these groups was divided into three study groups: untreated, treated with 0.05% Novacid, and treated with 400 mg/kg BMD. At day 42, inclusion of Novacid or BMD significantly (P < 0.05) improved the performance in the unchallenged groups relative to the control group. However, in E. coli-challenged groups, Novacid and BMD did not improve performance. Ileal digestibility of crude fat, crude protein, and gross energy were reduced in the Novacid group (P < 0.05). BMD and Novacid were equally effective in controlling ileal nutrient digestibility and feed coliform count (P < 0.05). Novacid reduced cecal E. coli and Salmonella count compared to BMD and control. Thus, a phytochemical feed supplement with organic acids and glucomannan could be an effective substitute for antibiotic growth promoters in broiler diets, but cannot replace antibiotics to counter potent infectious agents such as E. coli.
... Gibson and Roberfroid first proposed prebiotics in 1995 to promote symbiosis in gut microbiota [19]. Today, there is clear evidence that prebiotics enhances host's immune function [125][126][127][128], selectively favoring health-promoting bacteria, such as Lactobacilli and Bifidobacteria [129][130][131][132][133], employing potential adhesion sites of pathogenic strains, thereby exerting anti-adhesive properties and repressing the virulence of human pathogens per se [130,132,134]. ...
Article
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Probiotic therapy forms a new strategy for dental caries prevention. Probiotic microorganisms possess the ability to displace cariogenic microorganisms and colonize the oral cavity. They can produce various antimicrobial substances such as bacteriocins, bacteriocin-like peptides, lactic acid, and hydrogen peroxide. Dairy products may be ideal for probiotic administration in dental patients. Many other means have been proposed, primarily for those allergic to dairy components, such as capsules, liquid form, tablets, drops, lozenges, sweetened cakes, and ice creams. The last two forms can be used in a coaching approach for children and elderly patients who find it difficult to avoid sugary beverages in their daily routine and benefit from the suggestion of easy, cheap, and common forms of delicacies. In caries prevention, the concept of the effector strain is already considered an integral part of the contemporary caries cure or prevention strategy in adults. Adults, though, seem not to be favored as much as children at early ages by using probiotics primarily due to their oral microbiome's stability. In this non-systematic review we describe the modes of action of probiotics, their use in the cariology field, their clinical potential, and propose options to prevent caries through a patient coaching approach for the daily dental practice.
... The above results showed that the native KGM was good for the gut health of mice. Previous studies have shown that hydrolyzed konjac glucomannan was an effective prebiotic in mice (Elamir et al., 2008;Pan, Chen, Wu, Tang, & Zhao, 2009), even better than the native one (Chen, Fan, Chen, & Chan, 2005). In the present study, enzymatic degradation of native KGM at the given conditions mainly caused reduction of the MW but not major structural changes. ...
Article
Konjac glucomannan (KGM) with a molecular weight (MW) of 823.4 kDa was partially degraded by endo-1,4-β-mannanase. Two hydrolyzed KGM fractions (KGM-M-1: 147.2 kDa and KGM-M-2: 21.5 kDa) were characterized and applied to the animal tests in comparison with the native KGM. After oral feeding to the mice, KGM-M-1 and KGM-M-2 significantly increased the short chain fatty acids (SCFAs) in the colonic contents and the native KGM increased SCFAs in the cecum. The more significant effect of the native KGM in the cecum may be attributable to its high viscosity, slowing down the movement of intestinal microflora through the cecum, while the lower MW KGM-M-1 and KGM-M-2 could move more easily through the colon to be fermented by colonic bacteria. This new finding may be useful for future research and development of low-MW KGM polysaccharides through enzyme hydrolysis for the desired gut health benefits.
... For vaginal therapy, it would be beneficial for the patient that the probiotic bacteria persisted by colonising the epithelium (Reid and Bruce, 2001). The use of prebiotics was developed initially for health benefits of the intestinal ecosystem (Elamir et al., 2008; Gibson and Roberfroid, 1995; Gibson et al., 2005). The term prebiotic was used to describe materials (carbohydrates) which travel to the colon when ingested and therein promote the growth of desirable (probiotic) organisms (Gibson and Roberfroid, 1995). ...
Article
The aim of this study was to evaluate how konjac glucomannan hydrolysates (GMH) could support the healthy re-colonisation of vaginal microflora post infections. A total of 26 female patients (12 controls and 14 treatments) aged 18 to 25 suffering from vaginal infection were recruited for this study. Patients were assigned randomly into two groups to receive a standard antifungal treatment or a standard antifungal treatment plus pessary capsules containing 200 mg GMH (twice a week for thirty days). Patients were assessed on day zero, sixteen and thirty of the trial. Several parameters were determined including yeast and bacterial counts, the KOH test, pH, Gram staining and wet mount microscopic observations. The results showed that the counts of Candida were diminished completely with antifungal treatment for both groups. However, the total bacterial counts increased with time in the GMH pessary group unlike the control. The normalised average KOH scores were reduced sharply with time in both groups although in the control group scores started to increase after sixteen days. The normalised average white blood cell scores also decreased with time for both groups. Epithelial cell scores decreased only for the GMH pessary group while clue cells and yeast-like fungi decreased with time for both control and GMH pessary groups. These results indicate the improvement of vaginal health recovery (post antifungal treatment for Candida infection) and especially the presence of healthy microflora due to the introduction of GMH in the vagina. The data indicate that it would be worth examining further the health benefits of GMH in a vaginal health format with a view to employing the material as a prophylactic or therapeutic agent. It provides an alternative approach to reducing vaginal infections and promoting consumer health.
... KGM has long been used as a health food in China and Japan. KGM is regarded as a non-calorie food, the role of which has been displayed in weight loss and cholesterol reduction (Abdulmnem et al., 2008). The Food Chemicals Codex in the United States lists Konjac flour as a food additive (Zhang, Xie, & Gan, 2005). ...
Article
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Gums are naturally occurring components in plants, which are essentially cheap and plentiful. They have diverse applications as thickeners, emulsifiers, viscosifiers, sweeteners etc. in confectionary, and as binders and drug release modifiers in pharmaceutical dosage forms. However, most of the gums in their putative form are required in very high concentrations to successfully function as drug release modifiers in dosage forms due to their high swellability/solubility at acidic pH. Hence, gums need to be modified to alter their physicochemical properties. This article is aimed at discussing the modification of gums through derivatisation of functional groups, grafting with polymers, cross-linking with ions etc. The factors influencing these processes in the pursuit of making them suitable for modifying the drug release properties of pharmaceutical dosage forms and for other purposes is discussed with respect to optimization of their performance.
... Prebiotics have been shown to stimulate the immune system through in vitro and in vivo experiments (Torrecillas et al., 2007). Prebiotics can also inhibit growth of pathogenic microorganisms, such as Salmonella Typhimurium, Clostridium perfringens, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Propionibacterium acnes, and promote growth of probiotic species (Al-Ghazzewi and Tester, 2010;Elamir et al., 2008). Akiyama et al. (2002) reported that GOS can control S. aureus populations, which are often found in patients with atopic dermatitis. ...
Article
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To investigate the effects of ingestion of galactooligosaccharide (GOS) on skin pigmentation, we conducted cell experiments and clinical trials. The effect of GOS on melanin accumulation was assessed in vitro using B16F10 cells. Moreover, melanin and erythema indexes following GOS consumption were explored during a double-blind, randomized, and placebo-controlled study, which included subjects divided by stratified block randomization to placebo or GOS. No cytotoxicity was observed at 70 mg/mL or lower GOS in B16F10 melanoma cells. Melanin accumulation was inhibited at 14 mg/mL or higher GOS. Upon ultraviolet B (UVB) irradiation, the survival of HaCaT cells (control) was reduced to 69.0% lower than baseline. A protective effect of GOS was observed upon treatment with 14~35 mg/mL GOS; however at 70 mg/mL, cells showed 64% viability compared to control cells irradiated with UVB. Delta values (Δ melanin index), which indicate the difference from the baseline melanin level, were significantly different to placebo (P<0.01) after 8 weeks. In the GOS group, delta values (Δ erythema index), which indicate the difference from baseline erythema level, also significantly differed from the placebo group (P<0.05) after 8 weeks. Our results suggest that intake of prebiotic GOS inhibits skin pigmentation and may represent a novel nutritional approach for skin care.
... As glucomannans contain components which may have a positive effect on health (Al-Ghazzewi et al. 2007; Elamir et al. 2008; Sutherland et al. 2008), for instance by selectively stimulating the gut-friendly bacteria and inhibiting the pathogens, they serve as valuable 'functional foods'. According to Jones (2002) functional foods are defined broadly as 'foods that provide more than simple nutrition; they supply additional physiological benefit to the consumer'. ...
Article
Book abstract: A hydrocolloid is defined as a colloid system wherein the colloid particles are dispersed in water. A hydrocolloid has colloid particles spread throughout water and depending on the quantity of water available that can take place in different states, e.g., gel or sol (liquid). Hydrocolloids can be either irreversible (single-state) or reversible. For example, agar, a reversible hydrocolloid of seaweed extract, can exist in a gel and sol state, and alternate between states with the addition or elimination of heat. Many hydrocolloids are derived from natural sources. Agar-agar and carrageenan are extracted from seaweed; gelatin is produced by hydrolysis of proteins of bovine and fish origins, and pectin is extracted from citrus peel and apple pomace. Gelatin desserts like jelly or Jell-O are made from gelatin powder, another effective hydrocolloid. Hydrocolloids are employed in food mainly to influence texture or viscosity. This new and important book gathers the latest research from around the globe in the study of food hydrocolloids and highlights such topics as: collagen and gelatin extracted from skate skin, sucrose pectin interaction, utiliztion of glucomannans for health and others.
... In fact, glucomannans, especially from konjac, are widely applied in food industry as stabilizers, thickeners, viscosifiers and gelling agents [40,41]. Moreover, glucomannans are associated with a range of health applications which include controlling of glucose absorption [42], restricting the absorption of cholesterol from the gut into the blood stream [43], decreasing the risk of gut cancer [44], stimulating the immune system [45] and restricting the growth of pathogens in the gut and associated toxicity [46]. ...
... Prebiotics in general have been found to stimulate the immune system in vitro and in vivo (Swanson et al., 2002; Torrecillas et al., 2007; Yamada et al., 2003). They can also stimulate the growth of probiotics at the expense of pathogens, such as Salmonella typhimurium, Clostridium perfringens, Listeria monocytogens, E. coli, S. aureus and P. acnes (Ghazzewi and Tester 2010; Al-Ghazzewi et al., 2007, Elamir et al., 2008). Akiyama et al. (2002reported that glucooligosaccharides can be used to control the growth of S. aureus, which often infects or colonises patients with atopic dermatitis (Chase and Armstrong, 2012 ). ...
Article
This review discusses the role of pre- and probiotics with respect to improving skin health by modulating the cutaneous microbiota. The skin ecosystem is a complex environment covered with a diverse microbiota community. These are classified as either transient or resident, where some are considered as beneficial, some essentially neutral and others pathogenic or at least have the capacity to be pathogenic. Colonisation varies between different parts of the body due to different environmental factors. Pre- and probiotic beneficial effects can be delivered topically or systemically (by ingestion). The pre- and probiotics have the capacity to optimise, maintain and restore the microbiota of the skin in different ways. Topical applications of probiotic bacteria have a direct effect at the site of application by enhancing the skin natural defence barriers. Probiotics as well as resident bacteria can produce antimicrobial peptides that benefit cutaneous immune responses and eliminate pathogens. In cosmetic formulations, prebiotics can be applied to the skin microbiota directly and increase selectively the activity and growth of beneficial 'normal' skin microbiota. Little is known about the efficacy of topically applied prebiotics. Nutritional products containing prebiotics and/or probiotics have a positive effect on skin by modulating the immune system and by providing therapeutic benefits for atopic diseases. This review underlines the potential use of pre- and probiotics for skin health.
... Among the 11 specific types of microflora examined, two were found significantly changed: the frequency of bifidobacteria increased from 30% in control mice to 100% in konjac flour-fed mice and the log count of enterobacteriaceae increased from 6.0 in control mice to 6.6 in konjac flour-fed mice. A similar study was also conducted by Elamir et al. (2008) to examine the effects of konjac glucomannan oligosaccharides (KGMO) on the gut microflora of mice. They described that the KGMO was able to significantly reduce fecal Clostridium perfringens and Escherichia coli counts. ...
... Some dietary carbohydrates have also proved their efficacy in gut health by preventing the adhesion of pathogens (especially Escherichia coli and Salmonella enterica) to the gut wall (Becker and Galletti, 2008). Hydrolysed konjac glucomannan is an effective prebiotic in mice (Elamir et al., 2008; Pan et al., 2009); more effective than native konjac glucomannan (Chen et al., 2005). Human faecal gut models have reinforced this view (Connolly et al., 2010). ...
Article
Purpose – This paper aims to evaluate the effect of depolymerised glucomannan in regulating blood lipid and glucose concentrations. Design/methodology/approach – Twenty adult volunteers were recruited. Blood samples were taken at Day 0. The volunteers consumed drinks containing 3.0 g active glucomannan hydrolysates (AMH) for 14 days, after which time blood samples were retaken (Day 15). Blood samples were analysed to determine the blood lipid and glucose concentrations. Findings – The average fasting blood glucose at the start of the trial was 2.54 mmol/L but reduced slightly to 2.49 mmol/L after consumption of the glucomannan. The total average cholesterol at the start of the trial was higher (6.69 mmol/L) than desirable ( < 5.0 mmol/L). This was reduced after consuming the glucomannan to 6.44 mmol/L (3.74 per cent). The triglyceride content was also higher initially than recommended (2.88 mmol/L) but was reduced by 11.5 per cent. The high-density lipoprotein (HDL) was within the desirable range before and after consumption (1.57 and 1.52 mmol/L, respectively), while the average low-density lipoprotein (LDL) was higher than recommended ( < 3.0 mmol/L), representing 4.55 mmol/L and 4.40 mmol/L before and after consumption, respectively. Both parameters were reduced by over 3.0 per cent. The consumption of the glucomannan hydrolysates also reduced the total cholesterol/HDL and LDL/HDL ratios. Originality/value – The AMH was effective in lowering blood cholesterol and glucose concentrations. Consumption of such carbohydrates could prove useful for these physiological disorders. Further studies are desirable to characterise the exact mechanism.
... Moreover, the number of colony forming units (CFU) obtained from milk containing the konjac hydrolysates were significantly (p = 0.01) higher than those containing inulin. Elamir et al. [120] determined the effects of depolymerized mannans and specifically KGMH on the colonic microflora of mice. In addition, blood glucose and cholesterol were also measured. ...
Article
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Lignocellulose is the most plentiful non-food biomass and one of the most inexhaustible renewable resources on the planet, which is an alternative sustainable energy source for the production of second generation biofuels. Lignocelluloses are composed of cellulose, hemicellulose and lignin, in which the sugar polymers account for a large portion of the biomass. Cellulases belong to the glycoside hydrolase family and catalyze the hydrolysis of glyosidic linkages depolymerizing cellulose to fermentable sugars. They are multi-enzymatic complex proteins and require the synergistic action of three key enzymes: endoglucanase (E.C. 3.2.1.4), exoglucanase (E.C. 3.2.1.176) (E.C. 3.2.1.91) and β-glucosidase (E.C. 3.2.1.21) for the depolymerization of cellulose to glucose. Solid state fermentation, which holds growth of microorganisms on moist solid substrates in the absence of free flowing water, has gained considerable attention of late due its several advantages over submerged fermentation. The review summarizes the critical analysis of recent literature covering production of cellulase in solid state fermentation using advance technologies such as consolidated bioprocessing, metabolic engineering and strain improvement, and circumscribes the strategies to improve the enzyme yield.
... In general, the total detected increases in fecal total anaerobe counts (Chen et al. 2005). Similar phenomenon was observed where mannoligosaccharides significantly reduced fecal C. perfringens and Escherichia coli counts (Elamir et al. 2008). The effect of glucomannan hydrolysates added to the ultra-high temperature milk on the growth of lactic acid bacteria was evaluated (Al-Ghazzewi et al. 2007). ...
Article
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The corms of Amorphophallus muelleri Blume contain a large amount of glucomannan, a kind of polysaccharide that are commonly consumed by people as gelly foods. In order to improve the beneficial properties of glucomannan, we previously have established the enzymatic process to produce the mannoligosaccharides from flour of glucomannan using microbial mannanase. The effects of mannoligosaccharides on the growth modulation of human intestinal microbiota were investigated in this study. A set of in vitro single batch culture experiment was conducted to study the effect of mannooligosaccharides on human-origin Lactobacillus fermentum AA0014 and Lactobacillus plantarum FU0811. A modified MRS medium containing 10% (w/v) sucrose, glucomannan, and mannoligosaccharide was used instead of glucose as carbon source. The results showed the highest growth rate (0.13 h⁻¹) with both L. fermentum AA0014 and L. plantarum FU0811 in the presence of mannooligosaccharides. We confirmed this result by a similar in vitro experiment using human fecal samples of six healthy adults as innocula and analyzed the microbial population by fluorescence in situ hybridization (FISH). Lactobacilli were proliferated higher in the presence of mannoligosaccharide than other carbon sources, yielding the microbial proportion as much of 10.9% of total microbiota. Overall, this study demonstrated the potential use of mannoligosaccharides synthesized from A. muelleri glucomannan as prebiotic candidate of modulating the beneficial human intestinal microbiota.
... Glucomannans hydrolyzate (GMH) acts as a prebiotic by stimulating selectively the growth of gut-friendly bacteria and serving as valuable functional food. Like other polysaccharides, the polymers can be depolymerized with acids and enzymes (Al-Ghazzewi et al., 2014;Bateni et al., 2013;Elamir et al., 2008). ...
... With long-term feeding assays (Supplementary Figure 2), we found no significant differences in the relative food intakes of control and GMH treatment groups, suggesting that dietary restriction is probably not involved. From existing studies, we know that GMH can function as an effective prebiotic in mice (7). To test whether GMH extends life span through its potential impact on the gut microbiota, we quantified bacterial load (ie, the number of bacterial cells per gut) by plating the microbiota of surface-sterilized flies on solid medium (35). ...
Article
Dietary supplementation of glucomannan has been shown to have multiple health benefits, but its effect on life span has not been investigated. Here, we show that glucomannan hydrolysate (GMH) treatment extends mean life span of the model organism Drosophila melanogaster. To unravel the underlying mechanisms, we first examined the effect of GMH on the gut microbiota. We found that GMH treatment is associated with an elevated bacterial load in aged flies but overall has limited effects on the relative microbiota composition. We also demonstrated that GMH inhibits age-associated hyperproliferation of intestinal stem cells and thus delays the deterioration of gut integrity. Further analysis of the midgut transcriptome revealed that both EGFR/MAPK and JAK/STAT signaling pathways are suppressed in GMH groups. Multiple key regulators or effectors of EGFR/MAPK pathway, Ets21c, Mkp3, and Rho, are downregulated by GMH treatment. In the JAK/STAT pathway, major ligands (eg, Upd2 and Upd3) and negative feedback inhibitors (eg, Socs36e) are all significantly downregulated. Additionally, the expression of genes encoding antimicrobial peptides is elevated by GMH treatment. Taken together, our study shows that dietary supplementation of GMH can prolong life span, possibly through regulating gut proliferative homeostasis.
... With long-term feeding assays (Supplementary Figure 2), we found no significant differences in the relative food intakes of control and GMH treatment groups, suggesting that dietary restriction is probably not involved. From existing studies, we know that GMH can function as an effective prebiotic in mice (7). To test whether GMH extends life span through its potential impact on the gut microbiota, we quantified bacterial load (ie, the number of bacterial cells per gut) by plating the microbiota of surface-sterilized flies on solid medium (35). ...
Article
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Background Observational research has identified several mortality biomarkers; however, their responsiveness to change is unknown. We tested whether the Healthy Aging Index (HAI) and other mortality biomarkers were responsive to intentional weight loss (WL), which is associated with lower mortality risk in recent meta-analyses. Methods Older adults (70.3 ± 3.7 years) with obesity were randomized into a 6-month WL (n = 47) or weight stability (WS: ±5% baseline weight; n = 48) program. Baseline and 6-month HAI score (0–10) was calculated from component sum (each 0–2: systolic blood pressure, forced vital capacity [FVC], creatinine, fasting blood glucose [FBG], Montreal Cognitive Assessment), and gait speed, grip strength, Digit Symbol Substitution Test, FEV1, Interleukin-6, C-Reactive Protein, and Cystatin-C were assessed at baseline and 6 months. Results Mean baseline HAI was 3.2 ± 1.6. By 6 months, WL participants lost 8.87 (95% CI: −10.40, −7.34) kg, whereas WS participants remained weight stable. WL group reduced HAI score (WL: −0.75 [95% CI: −1.11, −0.39] vs WS: −0.22 [95% CI: −0.60, 0.15]; p = .04), and components changing the most were FBG (WL: −3.89 [95% CI: −7.78, 0.00] mg/dL vs WS: 1.45 [95% CI: −2.61, 5.50] mg/dL; p = .047) and FVC (WL: 0.11 [95% CI: −0.01, 0.23] L vs WS: −0.05 [95% CI: −0.17, 0.08] L; p = .06). Among other biomarkers, only Cystatin-C significantly changed (WL: −2.53 [95% CI: −4.38, −0.68] ng/mL vs WS: 0.07 [95% CI: −1.85, 1.98] ng/mL; p = .04). Combining treatment groups, 1 kg WL was associated with a 0.07 (95% CI: 0.03, 0.12) HAI reduction (p < .01). Conclusion Intentional WL via caloric restriction reduced HAI score by 0.53 points, largely attributable to metabolic and pulmonary improvements.
... In vivo studies in healthy animals (Elamir et al., 2008;Qin et al., 2014;Wan et al., 2015;Wang et al., 2016a), ulcerative colitis animals (Feng et al., 2015;Liu et al., 2016), and humans suffering from IBD (Suwannaporn et al., 2013) (Table 2) verified the prebiotic effects of DKGM. Mechanism studies revealed that oral administration of DKGM not only promotes the proliferation of probiotics (mainly Lactobacillus and Bifidobacterium), which is consistent with the in vitro results, but also influences the intes-tinal environment (increasing intestinal villi height and SCFAs) and reduces the levels of inflammatory factors (malondialdehyde, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β)). ...
Article
Konjac glucomannan (KGM) is a water-soluble polysaccharide obtained from the roots and tubers of konjac plants. Recently, a degraded product of KGM, depolymerized KGM (DKGM), has attracted attention because of its low viscosity, improved hydrophily, and favorable physiological functions. In this review, we describe the preparation of DKGM and its prebiotic effects. Other health benefits of DKGM, covering antioxidant and immune activity, are also discussed, as well as its safety. DKGM could be a candidate for use as a tool for the treatment of various diseases, including intestinal flora imbalance, and oxidative- and immune-related disorders.
... The use of prebiotics was developed initially for health benefits of the intestinal ecosystem (Elamir et al., 2008;Gibson and Roberfroid, 1995;Gibson et al., 2005). The term prebiotic was used to describe materials (carbohydrates) which travel to the colon when ingested and therein promote the growth of desirable (probiotic) organisms (Gibson and Roberfroid, 1995). ...
Article
Purpose This review focusses on the utilisation of pre- and probiotics for oral care and the state of knowledge at this time. Design/methodology/approach Pre – and probiotics describe beneficial carbohydrates and microbiota respectively for optimal gut health. The carbohydrates provide energy selectively for the gut-friendly bacteria. The use of both these type of carbohydrates and bacteria is however being expanded into other areas of the body – including the skin, vagina and oral cavity – for health related applications. Findings There is increased interest in both pre- and probiotics for oral care products. The importance of oral microflora and their selective substrates are discussed against a background of contemporary oral care approaches. The issues and benefits are discussed in this review. Originality/value It is clear that consumption of prebiotics and probiotics may play a role as potential prophylactic or therapeutic agents for reducing the presence of organisms in the mouth associated with tooth decay. In order to confirm a beneficial effect of pre – and probiotics further in vivo studies involving healthy human volunteers should be considered.
... Although no differences were found in the composition of the microbiota, a significant reduction in the activity of the enzymes involved in the metabolism of toxic compounds such as β-glucuronidase and nitroreductase was observed. Elamir et al. 64 tested the effects of KGM hydrolysates on the gut microbiota, as well as on the blood glucose and cholesterol in mice. The GMOS were able to modulate the gut microbiota by promoting the growth of bifidobacteria and lactobacilli and reducing the fecal Clostridium perfringens and E. coli counts. ...
Article
Glucomannans (GM) are polymers which can be found in natural resources, such as tubers, bulbs, roots, and in both hard- and softwoods. In fact, mannan-based polysaccharides represent the largest hemicellulose fraction in softwoods. In addition to their structural functions and their role as energy reserve, they have been assessed for their healthy applications, including their role as new source of prebiotics. This article summarizes the scientific literature regarding the manufacture and the functional properties of GM and their hydrolysis products with a special focus on their prebiotic activity.
... The hydrolysates promoted the growth of anaerobes and lactobacilli and reduced the Clostridium perfringens and Escherichia coli counts. In addition, the low blood glucose and cholesterol levels found for the treatment group could open an alternative for the treatment of subjects with diabetes or high cholesterol (Elamir et al., 2008). In connection with the cholesterol problems, González-Torres et al. (2015) demonstrated that GM and GM plus spirulina added to pork significantly block dietary cholesterol effects on lipoproteinemia or arylesterase activity in rats. ...
Chapter
A prebiotic is a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gut microbiota, thus conferring benefit(s) upon host health. Nowadays, there is a growing list of inexpensive and abundant potential prebiotics for which the scientific evidence, especially in humans, is not well established as for other commercial ones such as fructooligosaccharides (FOS), and therefore more research studies are needed. Among the most widely water-extracted oligosaccharides, from wood and agro-industrial wastes, with prebiotic activity are xylooligosaccharides (XOS), glucomannooligosaccharides (GMOS), and pectin-derived oligosaccharides (POS). This chapter includes scientific literature regarding the production, the manufacture, and the evaluation of the possible health benefits of this group of emerging prebiotics obtained from renewable sources.
... Glucomannans hydrolyzate (GMH) acts as a prebiotic by stimulating selectively the growth of gut-friendly bacteria and serving as valuable functional food. Like other polysaccharides, the polymers can be depolymerized with acids and enzymes (Al-Ghazzewi et al., 2014;Bateni et al., 2013;Elamir et al., 2008). ...
Chapter
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This chapter focuses on nutritional and anti-nutritional factors, traditional processes for the removal of anti-nutrients, processing for flour, starch and discusses resistant starch from Elephant Foot Yams (EFY). Also, industrial utilization of Amorphophallus konjac into konjac flour and gum, glucomannan (KGM) and its applications as a food and pharmaceutical supplements are reviewed. The procedure for starch extraction from EFY is described by Amani et al. The EFY has many medicinal properties. In India, it is used in Ayurvedic drugs in the treatment of inflammatory conditions, hemorrhoids, rheumatism and gastrointestinal disorders. This flour produces a high viscosity and forms a gel by alkaline coagulant such as calcium hydroxide or by combining with secondary gum or co-gelated gum such as K-carrageenan and xanthan gum. In recent decades, methods for the extraction and purification of konjac glucomannan (KGM) have been studied and developed.
... Moreover, the number of colony forming units (CFU) obtained from milk containing the konjac hydrolysates were significantly (p = 0.01) higher than those containing inulin. Elamir et al. [120] determined the effects of depolymerized mannans and specifically KGMH on the colonic microflora of mice. In addition, blood glucose and cholesterol were also measured. ...
Chapter
Cellulose, present in renewable lignocellulosic material, is considered to be the most abundant organic substrate on earth for production of hexose and pentose sugars, feedstock for fuel, and for other chemicals. Research on cellulase has progressed very rapidly in the past few decades with an emphasis on enzymatic hydrolysis of cellulose to hexose sugars. The enzymatic hydrolysis of cellulose requires the use of cellulase [1,4-(1,3:1,4)-β-D-glucan glucanohydrolase, EC 3.2.1.4], a multiple enzyme system consisting of endo-1,4,-β-D-glucanases [1,4-β-D-glucanases (CMCase, EC 3.2.1.4)], exo-1,4,-β-D-glucanases [1,4-β-D glucan cellobiohydrolase, FPA, EC 3.2.1.91], and β-glucosidase (cellobiase) (β-D-glucoside glucanohydrolase, EC 3.2.1.21). Major impediments to exploit the commercial potential of cellulases are the economic yield, stability, specificity, and above all, the cost of production. In the last few years, emphasis has been devoted mainly to submerged fermentation and less attention has been given to solid state fermentation (SSF). SSF refers to the process whereby microbial growth and product fermentation occur on the surface of solid materials. This process occurs in the absence of "free" water, where the moisture is absorbed to the solid matrix. The direct applicability of the product, the high product concentration, lower production cost, easy product recovery, and reduced energy requirement make SSF a promising technology for cellulase production. This chapter covers the production of cellulase in SSF using various lignocellulosic substrates, the microorganisms involved, cultural conditions, process parameters (ie, moisture content and water activity, mass transfer processes: aeration and nutrients diffusion, substrate particle size, temperature, pH, surfactants, etc.), bioreactor designs, and the strategies to improve enzyme yield.
... Moreover, the number of colony forming units (CFU) obtained from milk containing the konjac hydrolysates were significantly (p = 0.01) higher than those containing inulin. Elamir et al. [120] determined the effects of depolymerized mannans and specifically KGMH on the colonic microflora of mice. In addition, blood glucose and cholesterol were also measured. ...
Article
In recent year, konjac glucomannan (KGM) has attracted more attention due to its non-harmful and non-toxic properties, good biocompatibility, biodegradability and hydrophilic ability. Moreover, KGM and their derivatives have several importances in the multidirectional research areas such as nutritional, biotechnological and fine chemical fields. In the previous article, we have reviewed the nutritional aspects of KGM covering the various aspects of functional foods, food additives and their derivatives. This review aims at highlighting the diverse biomedical research conducted on KGM in the past ten years, covering therapies for anti-obesity, regulation in lipid metabolism, laxative effect, anti-diabetic, anti-inflammatory, prebiotic to wound dressing applications. Moreover, this review deals with global health aspects of KGM and the disparate health related factors associated with diseases and their control measures.
... Moreover, the number of colony forming units (CFU) obtained from milk containing the konjac hydrolysates were significantly (p = 0.01) higher than those containing inulin. Elamir et al. [120] determined the effects of depolymerized mannans and specifically KGMH on the colonic microflora of mice. In addition, blood glucose and cholesterol were also measured. ...
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Amorphophallus konjac (konjac) is one among the major vegetable (tuber) crops grown in Asian countries. In China and Japan, it has been used as food and food additives for more than 1000 years. Over the last few decades, the purified konjac flour, commonly known as konjac glucomannan (KGM), a dietary fiber hydrocolloidal polysaccharide, has been introduced as a food additives as well as dietary supplement in many Asian and European countries. The present article reviews the literature (up to January 2015) covering the development of various functional foods, food additives from KGMs and their derivatives, Also, this review deals with global nutritional aspects and value added products of konjac corm.The bioprocessing techniques such as preparation, purification, extraction of KGM from konjac flour and methods to improve quality of KGM are discussed.
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Mannose polymers are important non-starch polysaccharides in beers. In this study, thirty-six beer samples representing three categories based on materials, including all barley malt beer, barley malt with adjuncts beer and wheat beer, were selected to investigate the content as well as its correlation with beer physicochemical indices, degree of polymerization, molecular weight and existent form of mannose polymers. The results suggested that mannose polymers level was significantly high in the wheat beer (156.76 mg/L and 456.50 mg/L calculated as mannan and glucomannan, respectively). Degree of polymerization was 23–47 and 46–162 calculated as mannan and glucomannan, and the molecular weight was 3,744 - 7,632 Da and 7,470 - 26,262 Da, respectively. Average ratio of glucose to mannose in glucomannan was between 1.79 and 1.93 without significant difference among three groups. Mannose polymers possibly exist in mannan, glucomannan or both. The content had significantly positive correlation with the original extract and viscosity of beers. Their correlation coefficients indicated more important influence on beer viscosity than β-glucan. This preliminary study would be helpful for revealing the structure of mannose polymers and its effect on beer brewing as well as human health.
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The effects of banana powder(BP), konjac powder(KP), resistant dextrin(RD), corn starch(CS) and L-carnitine(LC) on gut microbiota and metabolites (SCFA) were evaluated in order to provide basic data for the development of weight-loss functional food. The gut microbiota profile using 16S V4 rDNA high-throughput sequencing technique suggested that the rats of RD, BP and CS group developed an increased richness and diversity in the gut bacterial community, while the abundance of the KP and LC group was not enhanced obviously. Verrucomicrobiaceae, Coprococcus-2 and Lachnospiraceae were the main bacterial genera in the CS, BP and RD group respectively, indicating their potential use as prebiotics. On the other hand, rats fed with BP, KP, CS and RD contributed higher total SCFA than those feeding with LC diet. Thus, RD, BP, CS, KP could moduate gut microbiota and increase the SCFA concentration, while the effect of LC are not apparent.
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The impact of ingesting glucomannans on health are not only limited to colonic focussed fermentation into short chain fatty acids (SCFAs) which might have some local health benefits, but also towards helping to treat disease states and enhance the body's immune system, both within the gut and in/on other parts of the body. The local and systemic role of hydrolysed glucomannans, especially konjac glucomannans in the mouth, oesophagus, stomach, small intestine, large intestine, gut-associated lymphoid tissue (GALT), skin and vagina are highlighted. Therapeutic applications are discussed.
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Type 2 diabetes (T2D) induced by obesity and high-fat diet is significantly associated with gut microbiota dysbacteriosis. Due to the first line clinical medicine of metformin has several intestinal drawbacks, combination usage of metformin with a prebiotic of konjac mannan-oligosaccharides (MOS) was conceived and implemented aiming to investigate whether there was some intestinal synergetic effects and how MOS would function. Composite treatment of metformin and MOS demonstrated synergistic effects on ameliorating insulin resistance and glucose tolerance, and repairing islet and hepatic histology. In addition, MF+MOS altered the gut community composition and structure by decreasing the relative abundances of family Rikenellaceae and order Clostridiales while increasing an unnamed OTU05945 of family S24-7, Akkermansia muciniphila, and Bifidobacterium pseudolongum. The present study suggested that usage of MOS could augment the hypoglycemic effects of metformin in association with gut microbiota modulation, which could provide references for further medication.
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The prebiotic potential of a konjac glucomannan hydrolysate (GMH) was investigated in vitro using batch cultures inoculated with human faeces. Bacterial enumeration was carried out using the culture independent technique, fluorescent in situ hybridisation (FISH), and short chain fatty acid (SCFA) production was monitored by gas chromatography. The populations of Bifidobacterium genus, Lactobacillus–Enterococcus group and the Atopobium group all significantly increased after GMH and inulin fermentation. The Bacteroides–Prevotella group had a lower end population after GMH fermentation while inulin gave an increase, although these differences were not significant. No significant differences in SCFA concentrations were observed between inulin and GMH. As with inulin, GMH produced selective stimulation of beneficial gut microbiota and a favourable SCFA profile. In order to confirm a beneficial effect of GMH further in vivo studies involving healthy human volunteers should be considered.
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Glucomannan polysaccharides may be hydrolysed to lower molecular weight molecules using acids or enzymes, specifically mannanases or cellulases. Mannanases (β-mannanases) hydrolyse β-(1-4)-linked mannose residues randomly in mannans whilst cellulases (β-glucanase) hydrolyse β-(1-4)-linked glucose residues. The molecular weight of the hydrolysate is clearly dependent on the amount of hydrolysis. One use of such hydrolysates has been towards their capacity to function as prebiotics. The relative efficacy of cellulase and/or mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria (LAB) has been evaluated. The LAB growth profiles (expressed in colony forming units, as a function of time) in UHT milk containing konjac glucomannan hydrolysed with cellulase were significantly greater than those containing glucose (control) or konjac glucomannan mannanase hydrolysates. An equivalent mixture (1:1) of cellulase-mannanase hydrolysates added to the UHT milk also showed significant improvement on the LAB growth profiles (compared to the glucose or mannanase alone hydrolysates). Different LAB strains showed some variation in growth profiles on the hydrolysates although this was not significant as a function of carbon source. Glucomannan hydrolysates produced with either mannanase or cellulase enzymes were effective growth promoters (carbon sources) of LAB. However, cellulase hydrolysates were most effective.
Chapter
Increasing scientific evidence has identified the correlation among dietary intake, the gut microbiome, and human health. Controlling the microbiome within the human gut through dietary modifications sheds light on novel nutritional strategies and clinical practices in reducing some chronic diseases. The emerging field of prebiotics, probiotics, and synbiotics is associated with the development of nutritional interventions, gut microbiome with positively impact health outcomes. Although there is strong evidence to demonstrate the complex link between gut microbiota and human health, substantial challenges still remain in delivering effective, stable and cost efficient foods with positive health outcomes, building personalized diets based on the gut microbiome profile, and standardizing clinical practices and establishing regulation. Dietary intervention, as a strong applicator, on microbiota and consequently on physiology and immune system, could play significant role in reducing the risk and progression of some chronic diseases including cancer and obesity. In this chapter, the authors focus on prebiotics as functional carbohydrate polymers, including traditional ones of human milk oligosaccharides (HMOS), fructooligosaccharides (FOS), and galactooligosaccharides (GOS), as well as potential ones of pectin oligosaccharides (POS), xylooligosaccharides (XOS), arabinoxylan oligosaccharides (AXOS), and glucomannan oligosaccharides (GMOS). To better understand the complex interplay of diet, nutrition and the microbiome in food development, as well as the effects of diet on the diversity of human microbiome, the contents of source, chemical structure, processing, physiological functionalities for each prebiotic will be covered.
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Scope: Konjac glucomannan oligosaccharides (KMOS) are prebiotics and may improve intestinal immunity through modulation of macrophage function. However, the underlying molecular mechanisms are still not clear. Methods and Results: Using a mouse model of dextran sulfated sodium (DSS)-induced acute colitis, we demonstrate here that KMOS (400 mg/kg/d) can ameliorate intestinal inflammation in a macrophage dependent manner. Oral exposure to KMOS prevented DSS-induced intestinal pathology, improved epithelium integrity, and decreased accumulation of colonic inflammatory leukocytes and cytokines. The therapeutic effects of KMOS are dependent on the function of macrophages, as depletion of macrophages abolished the effects. In colonic lamina propria of DSS-treated mice, as well as in vitro culture of bone marrow derived macrophages (BMDMs), KMOS skewed reprogramming of classically activated macrophages (CAM/M1) into alternatively activated macrophages (AAM/M2). We further determine that the activation of SIGNR1/phospho-c-Raf (S338)/phospho-p65 (S276)/acetyl-p65 (K310) pathway is responsible for KMOS-induced AAM/M2 polarization. Blockage of SIGNR1 abolished KMOS-induced AAM/M2 polarization of activated macrophages, expression of phospho-p65 (S276) in colonic macrophages, and alleviation of DSS-induced colitis in mice, suggesting that SIGNR1 is critical for macrophage responses to KMOS. Conclusions: This study reveals a SIGNR1-mediated macrophage-dependent pathway that supports regulatory function of KMOS in host immunity and intestinal homeostasis. This article is protected by copyright. All rights reserved
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Irregular and long time work schedules not only makes people feel fatigue, but also brings great risks of diseases, due to gastrointestinal disorder and immune dysfunction. Therefore, it has positive significance to help challenged people stay energetic and healthy with food supplement. Konjac oligosaccharide has shown various physiological benefits and been recommended in the fortification of functional foods. However, there have been few reports on its application aimed to simultaneously relieve physical fatigue and keep body healthy. In this paper, the potential prebiotic, immunoregulatory, and antifatigue activities of konjac oligosaccharide were evaluated in vitro and in vivo. The results showed that konjac oligosaccharide could promote probiotics growth and short chain fatty acids production in mice cecum. At the concentration of 50 to 200 μg/mL, konjac oligosaccharide could activate murine macrophage RAW 264.7 to secret NO and cytokines of IL‐10 and IL‐6. Moreover, this oligosaccharide could alleviate physical fatigue by prolonging exhaustive time, improving the level of superoxide dismutases and glutathione peroxidase, increasing the content of blood glucose, and decreasing the content of blood urea nitrogen. The results suggested that konjac oligosaccharide had prebiotic, immunoregulatory, and antifatigue effects, providing its application potential in functional food aimed at people with irregular and long time work.
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Konjac glucomannan is a kind of neutral polysaccharides with excellent biocompatibility and biodegradable activities. The recent studies on the applications of konjac glucomannan and its derivatives in pharmaceutical, bio-technical, fine chemical fields etc. were reviewed.
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Sprague-Dawley rats were fed diets containing 7.5% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among rats fed cholesterol, liver total lipid and cholesterol concentrations were significantly lower in groups fed pectin, psyllium and oat bran compared with cellulose-fed controls. Cholesterol feeding resulted in significantly greater liver cholesterol in rats fed cellulose, psyllium and oat bran but not in those fed pectin. Among rats fed cholesterol, total serum cholesterol levels were significantly lower in those fed pectin than in those fed psyllium, oat bran or cellulose. When cholesterol was fed, the oat bran-fed group had significantly higher butyrate and the pectin-fed group had significantly higher propionate concentrations in the hepatic portal vein than did cellulose-fed controls. The groups fed psyllium, oat bran and pectin all had significantly higher fecal neutral sterols than did the cellulose-fed group when cholesterol was fed. Without dietary cholesterol only pectin-fed rats had significantly higher fecal excretion of neutral sterols than those fed cellulose. Dietary fiber did not influence fecal acidic sterol excretion. However, the addition of cholesterol to these fiber diets was accompanied by a significantly higher bile acid excretion than that of animals fed cellulose without cholesterol. The results of this study indicate that soluble dietary fibers may exert their hypocholesterolemic effect by increasing excretion of fecal neutral sterols.
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Chronic constipation is a very frequent disease in western countries but fibres can often solve the problem. In the present study, authors tested the efficacy and the acceptability of glucomannans, hydrophylic carbohydrates with a high degree of viscosity, in 93 patients affected with chronic constipation. The multicentric, open and non-controlled study was divided into an initial phase (treatment with 1g of glucomannans t.i.d. for 1 month) and a maintenance phase (1g b.i.d. for one month). We evaluated both objective parameters (number of days per week with bowel movements and number of enemas) and abdominal symptoms. After one month all assessed parameters showed a statistically significant improvement lasting through the second month. Glucomannans were well accepted and devoid of relevant side-effects. In conclusion, considering their efficacy and tolerability, they can be proposed as an ideal therapeutic tool in the management of chronic constipation symptoms.
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Both chitosan and glucomannan have demonstrated hypocholesterolemic effects. A recent study in rats indicates that the combination of the two is also a potent hypocholesterolemic agent that increases fecal fat excretion. The objective of the present study was to determine the hypocholesterolemic effect of a supplement containing equal amounts of chitosan and glucomannan on blood lipid concentrations and fecal excretion of fat, neutral sterols and bile acids. Twenty-one overweight normocholesterolemic subjects (11 males and 10 females) were fed 2.4 g/day of a supplement containing equal amounts of chitosan and glucomannan. Prior to taking the supplement (initial period) and after 28 days (final period), blood was drawn for measurement of serum lipids and a three-day fecal sample collected for determination of fat, neutral sterol and bile acid excretion. Subjects maintained their normal dietary and activity patterns during the study. Caloric intake and intake of fat and dietary fiber (excluding the supplement) did not differ between the initial and final periods. Serum total, HDL and LDL cholesterol concentrations were significantly lower (p < 0.05) in the final period compared to the initial period. Serum triacylglycerol concentration did not change between periods. There was a trend towards greater fecal excretion of neutral sterols and bile acids (p = 0.13 and 0.16, respectively) in the final period. However, fecal fat excretion did not differ between periods. Serum cholesterol reduction by a chitosan/glucomannan supplement is likely mediated by increased fecal steroid excretion and is not linked to fat excretion.
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The present study was designed to evaluate effects of konjac glucomannan (KGM) supplement (3.6 g/day) for 28 days on blood lipid and glucose levels in hyperlipidemic type 2 diabetic patients and the possible mechanism for the reductions in blood lipid levels. Twenty-two diabetic subjects (age 64.2 + 8.4 years, BMI 25.5 + 3.2 kg/m(2)) with elevated blood cholesterol levels (fasting glucose between 6.7-14.4 mmol/L), but currently not taking lipid-lowering medication, were recruited to participate in a two 28-day period, randomized, double-blind, crossover clinical trial. Fasting blood samples drawn on the initial and final days of each period were determined for plasma lipids and glucose levels. Feces collected at the end of each experimental period were analyzed for neutral sterol and bile acid contents. Compared with placebo, KGM effectively reduced plasma cholesterol (11.1%, p = 0.0001, adjusted alpha = 0.006), LDL-cholesterol (20.7%, p = 0.0004, adjusted alpha = 0.006), total/HDL cholesterol ratio (15.6%, p = 0.0005, adjusted alpha = 0.007), ApoB (12.9%, p = 0.0001, adjusted alpha = 0.006) and fasting glucose (23.2%, p = 0.002, adjusted alpha = 0.008). Plasma triglyceride, HDL-cholesterol, LDL/HDL cholesterol, postprandial glucose and body weight were not significant after adjustment by the Bonferroni-Hochberg procedure. Fecal neutral sterol and bile acid concentrations were increased by 18.0% (p = 0.004) and 75.4% (p < 0.001), respectively, with KGM supplement. The KGM supplement improved blood lipid levels by enhancing fecal excretion of neutral sterol and bile acid and alleviated the elevated glucose levels in diabetic subjects. KGM could be an adjunct for the treatment of hyperlipidemic diabetic subjects.
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Acute gut disorder is a cause for significant medicinal and economic concern. Certain individual pathogens of the gut, often transmitted in food or water, have the ability to cause severe discomfort. There is a need to manage such conditions more effectively. The route of reducing the risk of intestinal infections through diet remains largely unexplored. Antibiotics are effective at inhibiting pathogens; however, these should not be prescribed in the absence of disease and therefore cannot be used prophylactically. Moreover, their indiscriminate use has reduced effectiveness. Evidence has accumulated to suggest that some of the health-promoting bacteria in the gut (probiotics) can elicit a multiplicity of inhibitory effects against pathogens. Hence, an increase in their numbers should prove effective at repressing pathogen colonisation if/when infectious agents enter the gut. As such, fortification of indigenous bifidobacteria/lactobacilli by using prebiotics should improve protection. There are a number of potential mechanisms for lactic acid bacteria to reduce intestinal infections. Firstly, metabolic endproducts such as acids excreted by these micro-organisms may lower the gut pH to levels below those at which pathogens are able to effectively compete. Also, many lactobacilli and bifidobacteria species are able to excrete natural antibiotics, which can have a broad spectrum of activity. Other mechanisms include an improved immune stimulation, competition for nutrients and blocking of pathogen adhesion sites in the gut. Many intestinal pathogens like type 1 fimbriated Escherichia coli, salmonellae and campylobacters utilise oligosaccharide receptor sites in the gut. Once established, they can then cause gastroenteritis through invasive and/or toxin forming properties. One extrapolation of the prebiotic concept is to simulate such receptor sites in the gut lumen. Hence, the pathogen is 'decoyed' into not binding at the host mucosal interface. The combined effects of prebiotics upon the lactic acid flora and anti-adhesive strategies may lead towards new dietary interventions against food safety agents.
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Pure soluble, recombinant and synthetic antigens, despite their better tolerability, are unfortunately often much less immunogenic than live or killed whole organism vaccines. Thus, the move towards the development of safer subunit vaccines has created a major need for more potent adjuvants. In particular, there is an urgent need for adjuvants capable of boosting cellular (Th1) immunity but without unacceptable toxicity. The adjuvant activity of aluminium compounds (aluminium phosphate or hydroxide) was first described by Glenny and colleagues in 1926. Surprisingly, despite the description of over one hundred adjuvants in the scientific literature, alum remains the only adjuvant approved for human use in the USA. Unfortunately, alum has no effect on cellular immunity and is faced with increasing concerns regarding potential for cumulative aluminium toxicity. Why then has alum not been replaced in human vaccines? Despite the enormous number of candidates, potency has invariably been associated with increased toxicity, and this more than anything else has precluded their use, particularly in prophylactic vaccines where safety issues are paramount. Hence, there is a major unmet need for a safe efficacious adjuvant capable of boosting cellular plus humoral immunity. The extensive data on inulin-based adjuvants indicate that these are excellent candidates to replace alum as the adjuvant of choice for many vaccines. Particular advantages offered by inulin-based adjuvants is that they induce cellular in addition to humoral immunity and offer excellent safety, tolerability, ease of manufacture and formulation. Thus, adjuvants based on inulin have enormous potential for use in vaccines against both pathogens and cancer.
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Mice were fed either a high fat diet or a high fat diet containing 1% mannooligosaccharides (MOS) for twelve weeks. The effects of MOS on fat accumulation and excretion were examined. After twelve weeks, the percentage weight of the fat and hepatic triglyceride level were significantly lower in the MOS group than that of the control group (p < 0.05 and p < 0.01 respectively). Furthermore, the serum triglyceride level had a decreasing tendency in the MOS group (p = 0.058). On the other hand, the fecal triglyceride level as well as the amount of fat excreted significantly increased in the MOS group (p < 0.05). This study showed that the administration of MOS lessened the fat accumulation in the parametrial adipose tissue and the liver while at the same time increased the amount of fat being excreted. These results indicate that MOS may prevent the fat storage through inhibiting the intestinal absorption of dietary fat in a high fat diet.
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In this study, the bactericidal effects of Japanese alkaline foods on food-poisoning bacteria were evaluated. Konjac is an alkaline food soaked in calcinated calcium (the pH of konjac fluid ranges from 11.42 to 12.53). Konjac fluids completely inactivated Escherichia coli, enterohemorrhagic E. coli O157:H7 and E. coil O26:H9, Salmonella Enteritidis, Vibrio parahemolyticus. and Staphylococcus aureus. The initial level of 6 log CFU/ml dramatically decreased after incubation with konjac fluid, and no viable gram-negative bacterium cells could be detected within 1 to 2 days and no viable S. aureus cells could be detected within 3 to 5 days. On the other hand, treatment with konjac fluid was also effective in reducing levels of spore-forming bacteria (Bacillus subtilis, Bacillus cereus, Clostridium perfringens, and Clostridium botulinum type E and type A). At least a 4-log reduction of spore-forming bacteria was obtained in konjac fluid within 7 to 14 days. Vegetative cells were more susceptible to konjac fluid than spores were. When the initial cell count was 6 log CFU/ml, a few surviving spores remained for 60 to 90 days, but no spores could be detected after 120 days. When the initial count of spore-forming bacteria was 3 to 4 log CFU/ml, the cells considered vegetative were completely inactivated within I to 3 days. Repeated treatment with konjac fluid caused complete inactivation of spores in less than 1 to 3 days. Our studies indicate that konjac fluid, which has a long history of use in food, will control food-poisoning bacterial contamination during the production or preservation of konjac and other foods and has a preventive effect on bacteria that can cause severe disease at uniquely low levels.
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Konjac glucomannan hydrolysate was derived enzymatically from konjac flour under optimal conditions. A number of culture strains of lactobacilli and bifidobacteria were grown on De Man, Rogosa and Sharpe (MRS) media supplemented with the hydrolysate. This hydrolysate stimulated the growth of all strains examined. Colony sizes of those strains grown on konjac hydrolysate were significantly (P = 0.001) bigger than those grown on pectin or xylan hydrolysates. Bacterial growth profiles were also conducted on nutrient agar (MRS or modified MRS agar containing konjac hydrolysate) using single strains of lactobacilli or bifidobacteria (Lactobacillus acidophilus, Lactobacillus casei or Bifidobacterium adolescentis), single pathogen cultures (Escherichia coli or Listeria monocytogenes) or mixed bacterial cultures (from chicken breast extract). Although the growth of lactobacilli inhibited the growth of pathogens (single or mixed culture) the pathogens could not grow on the konjac hydrolysate as a sole carbon source. Microbial growth profiles using konjac hydrolysate or inulin in UHT milk were also investigated. The results showed that the numbers of colony forming units (cfu) obtained from milk containing the konjac hydrolysate were significantly (P = 0.01) higher than those containing inulin. It is suggested that the unique properties of konjac hydrolysate make it universally valuable as a prebiotic which can be applied to a wide range of foods, feeds and healthcare/pharmaceutical products. Copyright © 2007 Society of Chemical Industry
Article
550 seven-wk-old LACA mice were used in 3 batches for studying the inhibitory effect of refined Amorphophallus konjac (Konjaku powder) on MNNG-induced lung cancers. The mice (within each batch) were randomly allocated into four groups, namely, positive control (MNNG), Amorphophallus konjac (A. K.), complex (MNNG+A. K.), and blank control (C) groups. In MNNG group, MNNG (250 micrograms) was injected intravenously once every five days for seven times in each mouse, the total dosage of MNNG being 1.75 mg. In A. K. group, according to w/w, 8% A. K. was well mixed into 92% common diet for long-term breeding. In the complex group, MNNG was given as that in MNNG group and the mice were kept as those in A. K. group. The mice in MNNG group and in C group were all maintained on common diet. The results showed different degrees of inhibitory and preventive effect of refined A. K. on MNNG-induced lung cancers. Refined A. K. not only exerted effect on the number of induced cancer and precancerous lesions, causing a drop in cancer rate from 70.87% to 19.38% and the mean number of cancer and precancerous lesions in each animal, but also altered the constituent ratio of the kinds of tumors, showing a decrease in malignancy (adenoma with malignant change), absence of adenocarcinoma, and relative increase in benign adenoma. The results of experiments in 3 batches also exhibited good reproducibility as well as absence of adverse reaction to Konjaku powder.
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Five sources of dietary fiber were compared for their effect on blood and liver cholesterol. The effects of soybean fiber, rice bran (full fat), oat bran, barley bran and mixed bran on total blood cholesterol concentrations and liver cholesterol concentrations were measured in beef-fed C57BL/6 male mice. Each diet contained cooked beef, beef tallow, corn starch and 7% dietary fiber from one of the five fiber sources. A control group consumed a fiber-free diet. Dietary cholesterol was provided by the beef and beef tallow only. The experimental diets were fed for 3 wk; blood and liver were collected when the mice were 18 wk old. The liver cholesterol concentration in the rice bran-fed group was the lowest of the six diet groups and was significantly different than concentrations in the oat bran-fed group and the barley bran-fed group (P less than 0.05). The oat bran, mixed bran, and barley bran did not significantly lower blood cholesterol in the mice. Both the soybean fiber and rice bran diet groups had significantly lower total blood cholesterol than did the fiber-free controls (P less than 0.05). The soybean fiber group also had significantly lower blood cholesterol than the mixed-bran group.
Article
An eight-week double-blind trial was conducted to test purified glucomannan fiber as a food supplement in 20 obese subjects. Glucomannan fiber (from konjac root) or placebo was given in 1-g doses (two 500 mg capsules) with 8 oz water, 1 h prior to each of three meals per d. Subjects were instructed not to change their eating or exercise patterns. Results showed a significant mean weight loss (5.5 lbs) using glucomannan over an eight-week period. Serum cholesterol and low-density lipoprotein cholesterol were significantly reduced (21.7 and 15.0 mg/dl respectively) in the glucomannan treated group. No adverse reactions to glucomannan were reported.
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Because the human gut microbiota can play a major role in host health, there is currently some interest in the manipulation of the composition of the gut flora towards a potentially more remedial community. Attempts have been made to increase bacterial groups such as Bifidobacterium and Lactobacillus that are perceived as exerting health-promoting properties. Probiotics, defined as microbial food supplements that beneficially affect the host by improving its intestinal microbial balance, have been used to change the composition of colonic microbiota. However, such changes may be transient, and the implantation of exogenous bacteria therefore becomes limited. In contrast, prebiotics are nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacterial species already resident in the colon, and thus attempt to improve host health. Intake of prebiotics can significantly modulate the colonic microbiota by increasing the number of specific bacteria and thus changing the composition of the microbiota. Nondigestible oligosaccharides in general, and fructooligosaccharides in particular, are prebiotics. They have been shown to stimulate the growth of endogenous bifidobacteria, which, after a short feeding period, become predominant in human feces. Moreover, these prebiotics modulate lipid metabolism, most likely via fermentation products. By combining the rationale of pro- and prebiotics, the concept of synbiotics is proposed to characterize some colonic foods with interesting nutritional properties that make these compounds candidates for classification as health-enhancing functional food ingredients.
Article
The effects of the soluble fiber konjac glucomannan (GM) on serum cholesterol concentrations were investigated in 63 healthy men in a double-blind crossover, placebo-controlled study. After a 2-wk baseline period, the subjects were given 3.9 g GM or placebo daily for 4 wk. After a washout period of 2 wk, crossover took place, followed by another 4 wk of treatment. The subjects were encouraged not to change their ordinary diets or general lifestyle during the investigation. GM fibers reduced total cholesterol (TC) concentrations by 10% (P < 0.0001), low-density-lipoprotein cholesterol (LDL-C) concentrations by 7.2% (P < 0.007), triglycerides by 23% (P < 0.03), and systolic blood pressure by 2.5% (P < 0.02). High-density-lipoprotein cholesterol (HDL-C) and the ratio of LDL-C to HDL-C did not change significantly. No change in diastolic blood pressure or body weight was observed. No adverse effects were observed. The results of this study show that GM is an effective cholesterol-lowering dietary adjunct.
Article
Certain indigestible oligosaccharides may benefit gastrointestinal tract health via fermentation and proliferation of desirable bacterial species. The purpose of this study was to elucidate effects of selected oligosaccharides on cecal and fecal short-chain fatty acid (SCFA) concentration, pH, total large bowel wet weight and wall weight, and gut microbiota levels in rats. Fifty male Sprague-Dawley rats were randomly assigned to one of five treatments: 1) control diet; 2) control diet + 5% microcrystalline cellulose (5% CC); 3) control diet + 5% CC + 6% fructooligosaccharides; 4) control diet + 5% CC + 6% oligofructose; or 5) control diet + 5% CC + 6% xylooligosaccharides. The control diet consisted of (dry matter basis) 20% protein, 65% carbohydrate, 10.5% fat, vitamin and mineral mixes. The duration of the study was 14 d. The oligofructose- and fructooligosaccharide-containing diets resulted in higher cecal butyrate concentrations compared with the control, cellulose and xylooligosaccharide diets. Generally, total cecal SCFA pools were higher while pH was lower from ingesting oligosaccharide-containing diets compared with control or cellulose diets. Cecal total weight and wall weight were higher from oligosaccharide consumption, whereas colonic total wet weight was higher for rats consuming xylooligosaccharides compared with other treatments; colon wall weight was unaffected by treatments. Cecal bifidobacteria and total anaerobes were higher whereas total aerobes were lower in rats fed oligosaccharide diets compared with those fed the control diet. Cecal lactobacilli levels were unaffected by treatment. Dietary incorporation of fermentable, indigestible oligosaccharides, by providing SCFA, lowering pH, and increasing bifidobacteria, may be beneficial in improving gastrointestinal health.
Article
Konjac (konnyaku) glucomannan was examined for its degradation in human intestines and fermentation products. The konjac glucomannan was degraded almost 100% by soluble enzymes in human feces to give 4-O-beta-D-mannopyranosyl-D-mannopyranose (beta-1,4-D-mannobiose), 4-O-beta-D-glucopyranosyl-D-glucopyranose (cellobiose), 4-O-beta-D-glucopyranosyl-D-mannopyranose, and small amounts of glucose and mannose. These three disaccharides were further degraded by a cell-associated enzyme(s) to glucose or mannose, or to both. Konjac glucomannan underwent fermentation by intestinal anaerobic bacteria and produced formic acid, acetic acid, propionic acid, and 1-butyric acid. These fatty acids were different in their proportions among test subjects, their total amounts ranging from 17.1% to 48.8% of the initial konjac glucomannan.
Article
Prebiotics induce changes in the population and metabolic characteristics of the gastrointestinal bacteria, modulate enteric and systemic immune functions, and provide laboratory rodents with resistance to carcinogens that promote colorectal cancer. There is less known about protection from other challenges. Therefore, mice of the B6C3F1 strain were fed for 6 wk a control diet with 100 g/kg cellulose or one of two experimental diets with the cellulose replaced entirely by the nondigestible oligosaccharides (NDO) oligofructose and inulin. From each diet, 25 mice were challenged by a promoter of colorectal cancer (1,2-dimethylhydrazine), B16F10 tumor cells, the enteric pathogen Candida albicans (enterically), or were infected systemically with Listeria monocytogenes or Salmonella typhimurium. The incidences of aberrant crypt foci in the distal colon after exposure to dimethylhdrazine for mice fed inulin (53%) and oligofructose (54%) were lower than in control mice (76%; P < 0.05), but the fructans did not reduce the incidence of lung tumors after injection of the B16F10 tumor cells. Mice fed the diets with fructans had 50% lower densities of C. albicans in the small intestine (P < 0.05). A systemic infection with L. monocytogenes caused nearly 30% mortality among control mice, but none of the mice fed inulin died, with survival intermediate for mice fed oligofructose. Mortality was higher for the systemic infection of S. typhimurium (>80% for control mice), but fewer of the mice fed inulin died (60%; P < 0.05), with mice fed oligofructose again intermediate. The mechanistic basis for the increased resistance provided by dietary NDO was not elucidated, but the findings are consistent with enhanced immune functions in response to changes in the composition and metabolic characteristics of the bacteria resident in the gastrointestinal tract.
Article
Seventy-two Holstein calves were used to study the effect of feeding antibiotics or mannan oligosaccharides (MOS) in milk replacer. Calves were fed a 20% protein, 20% fat milk replacer containing antibiotics (400 g/ton neomycin + 200 g/ton oxytetracycline), MOS (4 g of Bio-Mos/d), or no additive (control) for 5 wk. Milk replacer was reconstituted to 12.5% dry matter and fed at 12% of birth weight during wk 1 and 14% of birth weight in wk 2 to 5. Fecal scores were monitored 3 times per week; body weight, heart girth, withers height, hip height, and hip width were measured at birth and weekly to 6 wk of age. Addition of MOS or antibiotics increased the probability of normal scores for fecal fluidity, scours severity, and fecal consistency as compared to control calves during the course of the study. Consumption of calf starter increased at a faster rate in calves fed MOS, and these calves consumed more calf starter after weaning (wk 6), than those fed antibiotic. No treatment differences in growth measures, total blood protein, or blood urea nitrogen were detected during the trial. Addition of MOS or antibiotics to milk replacer improved fecal scores in calves. Feed intake was improved in MOS-fed calves compared to antibiotic-fed calves, but this difference did not result in growth differences during the experimental period. The results suggest that antibiotics in milk replacers can be replaced with compounds such as mannan oligosaccharides to obtain similar calf performance.
Article
In nutritional sciences there is much interest in dietary modulation of the human gut. The gastrointestinal tract, particularly the colon, is very heavily populated with bacteria. Most bacteria are benign; however, certain gut species are pathogenic and may be involved in the onset of acute and chronic disorders. Bifidobacteria and lactobacilli are thought to be beneficial and are common targets for dietary intervention. Prebiotic is a non-viable food ingredient selectively metabolized by beneficial intestinal bacteria. Dietary modulation of the gut microflora by prebiotics is designed to improve health by stimulating numbers and/or activities of the bifidobacteria and lactobacilli. Having an 'optimal' gut microflora can increase resistance to pathogenic bacteria, lower blood ammonia, increase stimulation of the immune response and reduce the risk of cancer. This chapter examines how prebiotics are being applied to the improvement of human health and reviews the scientific evidence behind their use.
Article
The activities of the bacteria resident in the colon of companion animals can have an impact upon the health of the host. Our understanding of this microbial ecosystem is presently increasing due to the development of DNA-based microbiological tools that allow identification and enumeration of nonculturable microorganisms. These techniques are changing our view of the bacteria that live in the gut, and they are facilitating dietary-intervention approaches to modulate the colonic ecosystem. This is generally achieved by the feeding of either live bacteria (probiotics) or nondigestible oligosaccharides (prebiotics) that selectively feed the indigenous probiotics. Feeding studies with a Lactobacillus acidophilus probiotic have shown positive effects on carriage of Clostridium spp. in canines and on recovery from Campylobacter spp. infection in felines. Immune function was improved in both species. Prebiotic feeding studies with lactosucrose and fructo-oligosaccharides in both cats and dogs have shown positive effects on the microflora balance. Recently synbiotic forms (a probiotic together with a prebiotic) targeted at canines have been developed that show promise as dietary-intervention tools.
Article
Inulin-type fructans (beta(2,1)fructans) extracted from chicory roots (Cichorium intybus) are prebiotic food ingredients, which in the gut lumen are fermented to lactic acid and SCFA. Research in experimental animal models revealed that inulin-type fructans have anticarcinogenic properties. A number of studies report the effects of inulin-type fructans on chemically induced pre-neoplastic lesions (ACF) or tumours in the colon of rats and mice. In twelve studies, there were twenty-nine individual treatment groups of which twenty-four measured aberrant crypt foci (ACF) and five measured tumours. There was a significant reduction of ACF in twenty-one of the twenty-four treatment groups and of tumour incidence in five of the five treatment groups. Higher beneficial effects were achieved by synbiotics (mixtures of probiotics and prebiotics), long-chain inulin-type fructans compared to short-chain derivatives, and feeding high-fat Western style diets. Inulin-type fructans reduced tumour incidence in APC(Min) mice in two of four studies and reduced growth and metastasising properties of implanted tumour cells in mice (four studies). The effects have been reported to be associated with gut flora-mediated fermentation and production of butyrate. In human cells, inulin-derived fermentation products inhibited cell growth, modulated differentiation and reduced metastasis activities. In conclusion, evidence has been accumulated that shows that inulin-type fructans and corresponding fermentation products reduced the risks for colon cancer. The involved mechanisms included the reduction of exposure to risk factors and suppression of tumour cell survival. Thus, this specific type of dietary fibre exerted both blocking agent and suppressing agent types of chemopreventive activities.
Article
This paper evaluates the effect of the adjunct of the hydrosoluble fiber glucomannan to a Step-One-Diet in 40 plasma hypercholesterolemic children, during a randomized controlled trial, to reduce plasma cholesterol. All the subjects recruited underwent an 8-week run in diet period; a Step-One-Diet was prescribed. After that, they were randomly allocated to one of two groups: Step-One-Diet only (control), and Step-One-Diet plus glucomannan in gelatine capsules. After another 8 weeks of treatment, the results were compared within and between the two groups. Glucomannan treated group showed decreased values in plasma total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) vs. control group after 8 weeks of treatment. The percentage decrease showed a statistically significant difference between sex groups. Decreases were observed in favor of female vs. male children in TC (24% vs. 9%) and LDL-C (30% vs. 9%). These results suggest that glucomannan may represent a rationale adjunct to diet therapy in primary prevention in high risk hypercholesterolemic children.
Article
The prebiotic role of intact konjac glucomannan (KGM) is contradictory. Short-chain glucomannan may cause a greater or faster effect on colonic microflora compared with KGM. Therefore, time-course and dose-dependent studies were conducted to examine and compare effects of unhydrolyzed KGM with those of acid-hydrolyzed glucomannan (KH) on cecal and fecal microflora. Short-chain fatty acid concentrations in cecal content were also determined. Seven-week-old male Balb/c mice were fed 5% (w/w) cellulose and KGM or KH diets for 2 or 4 wk in a time-course study. Cecal total anaerobes, bifidobacteria, Clostridium perfringens and Escherichia coli counts, and short-chain fatty acid concentrations were determined. In a subsequent dose-dependent study, Balb/c mice were fed AIN-93 fiber-free diets supplemented with 2.5%, 5%, or 7.5% of KGM or KH for 4 wk. Anaerobes, bifidobacteria, C. perfringens, and E. coli were enumerated in the cecal content and feces. KGM and KH significantly increased cecal anaerobes and bifidobacteria counts at weeks 2 and 4, respectively, compared with cellulose. In contrast, KGM and KH significantly decreased cecal C. perfringens counts only at week 4. Acetate and propionate concentrations in cecal contents were increased by KGM and KH diets at weeks 2 and 4, respectively. In the dose-dependent study, KH increased cecal bifidobacteria counts only at the 2.5% level but increased fecal bifidobacteria count and suppressed C. perfringens counts at each dose level as compared with KGM. Hydrolyzed glucomannan exerts a greater prebiotic effect than does KGM in Balb/c mice.
Article
Interest has been recently rekindled in short chain fatty acids (SCFAs) with the emergence of prebiotics and probiotics aimed at improving colonic and systemic health. Dietary carbohydrates, specifically resistant starches and dietary fiber, are substrates for fermentation that produce SCFAs, primarily acetate, propionate, and butyrate, as end products. The rate and amount of SCFA production depends on the species and amounts of microflora present in the colon, the substrate source and gut transit time. SCFAs are readily absorbed. Butyrate is the major energy source for colonocytes. Propionate is largely taken up by the liver. Acetate enters the peripheral circulation to be metabolized by peripheral tissues. Specific SCFA may reduce the risk of developing gastrointestinal disorders, cancer, and cardiovascular disease. Acetate is the principal SCFA in the colon, and after absorption it has been shown to increase cholesterol synthesis. However, propionate, a gluconeogenerator, has been shown to inhibit cholesterol synthesis. Therefore, substrates that can decrease the acetate: propionate ratio may reduce serum lipids and possibly cardiovascular disease risk. Butyrate has been studied for its role in nourishing the colonic mucosa and in the prevention of cancer of the colon, by promoting cell differentiation, cell-cycle arrest and apoptosis of transformed colonocytes; inhibiting the enzyme histone deacetylase and decreasing the transformation of primary to secondary bile acids as a result of colonic acidification. Therefore, a greater increase in SCFA production and potentially a greater delivery of SCFA, specifically butyrate, to the distal colon may result in a protective effect. Butyrate irrigation (enema) has also been suggested in the treatment of colitis. More human studies are now needed, especially, given the diverse nature of carbohydrate substrates and the SCFA patterns resulting from their fermentation. Short-term and long-term human studies are particularly required on SCFAs in relation to markers of cancer risk. These studies will be key to the success of dietary recommendations to maximize colonic disease prevention.
Article
Constipation and encopresis are common problems in children. Still today, the role of fiber in the treatment of chronic constipation in childhood is controversial. The aim of our study was to evaluate whether fiber supplementation is beneficial in the treatment of children with functional constipation with or without encopresis. We used glucomannan as the fiber supplement. We evaluated the effect of fiber (glucomannan, a fiber gel polysaccharide from the tubers of the Japanese Konjac plant) and placebo in children with chronic functional constipation with and without encopresis in a double-blind, randomized, crossover study. After the initial evaluation, the patients were disimpacted with 1 or 2 phosphate enemas if a rectal impaction was felt during rectal examination. Patients continued with their preevaluation laxative. No enemas were given during each treatment period. Fiber and placebo were given as 100 mg/kg body weight daily (maximal 5 g/day) with 50 mL fluid/500 mg for 4 weeks each. Parents were asked to have children sit on the toilet 4 times daily after meals and to keep a stool diary. Age, frequency of bowel movements into the toilet and into the undergarment, presence of abdominal pain, dietary fiber intake, medications, and the presence of an abdominal and/or a rectal fecal mass were recorded on a structured form at the time of recruitment and 4 weeks and 8 weeks later. Children were rated by the physician as successfully treated when they had > or =3 bowel movements/wk and < or =1 soiling/3 weeks with no abdominal pain in the last 3 weeks of each 4-week treatment period. Parents made a global assessments to whether they believed that the child was better during the first or second treatment period. Forty-six chronically constipated children were recruited into the study, but only 31 children completed the study. These 31 children (16 boys and 15 girls) were 4.5 to 11.7 years of age (mean: 7 +/- 2 years). All children had functional constipation; in addition, 18 had encopresis when recruited for the study. No significant side effects were reported during each 4-week treatment period. Significantly fewer children complained of abdominal pain and more children were successfully treated while on fiber (45%) as compared with placebo treatment (13%). Parents rated significantly more children (68%) as being better on fiber versus 13% as being better on placebo. The initial fiber intake was low in 22 (71%) children. There was no difference in the percentage of children with low fiber intake living in the United States (70%) and Italy (71%). Successful treatment (physician rating) and improvement (parent rating) were independent of low or acceptable initial fiber intake. The duration of chronic constipation ranged from 0.6 to 10 years (mean: 4.0 +/- 2.5 years). Duration of constipation did not predict response to fiber treatment. Children with constipation only were significantly more likely to be treated successfully with fiber (69%) than those with constipation and encopresis (28%). We found glucomannan to be beneficial in the treatment of constipation with and without encopresis in children. Symptomatic children who were already on laxatives still benefited from the addition of fiber. Therefore, we suggest that we continue with the recommendation to increase the fiber in the diet of constipated children with and without encopresis.
Effect of adding mannan oligosaccharide (BioMos) to the milk replacer for calves
  • R A Dvorak
  • K A Jacques
Dvorak, R.A. and Jacques, K.A. (1997), ''Effect of adding mannan oligosaccharide (BioMos) to the milk replacer for calves'', Journal of Animal Science, Vol. 75, Supplement 1, p. 22.
The chemical, physical and nutritional properties of the plant polysaccharide konjac glucomannan
  • S Khanna
Khanna, S. (2003), ''The chemical, physical and nutritional properties of the plant polysaccharide konjac glucomannan'', PhD thesis, Glasgow Caledonian University, Glasgow.
Al-Ghazzewi can be contacted at: f.h.alghazzewi@glycologic.co.uk To purchase reprints of this article please e-mail: reprints@emeraldinsight.com Or visit our web site for further details
  • H Farage
Farage H. Al-Ghazzewi can be contacted at: f.h.alghazzewi@glycologic.co.uk To purchase reprints of this article please e-mail: reprints@emeraldinsight.com Or visit our web site for further details: www.emeraldinsight.com/reprints