Articles de revues : « Human colon fermentation »

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Arrigoni, Eva, Fred Brouns et Renato Amadò. « Human gut microbiota does not ferment erythritol ». British Journal of Nutrition 94, n^o 5 (novembre 2005) : 643–46. http://dx.doi.org/10.1079/bjn20051546.

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Erythritol, a naturally occurring polyol, is gaining attention as a bulk sweetener for human nutrition. Industrially, it is produced from glucose by fermentation. From various studies it is known to be non-cariogenic. Moreover, it is rapidly absorbed in the small intestine and quantitatively excreted in the urine. Only about 10 % enters the colon. Earlier in vitro experiments showed that erythritol remained unfermented for a fermentation period of 12 h. In order to investigate whether fresh human intestinal microbiota is able to adapt its enzyme activities to erythritol, a 24 h lasting fermentation was carried out under well-standardised in vitro conditions. For comparison maltitol, lactulose and blank (faecal inoculum only) were incubated as well. Fermentation patterns were established by following total gas production, hydrogen accumulation, changes in pH value, SCFA production and substrate degradation. Taking all fermentation parameters into account, erythritol turned out to be completely resistant to bacterial attack within 24 h, thus excluding an adaptation within that period. Since under in vivo conditions more easily fermentable substrates enter the colon continuously, it seems very unlikely that erythritol will be fermented in vivo.

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Hill, M. J. « Bacterial fermentation of complex carbohydrate in the human colon ». European Journal of Cancer Prevention 4, n^o 5 (octobre 1995) : 353–58. http://dx.doi.org/10.1097/00008469-199510000-00004.

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Probert, H. M., et G. R. Gibson. « Development of a fermentation system to model sessile bacterial populations in the human colon ». Biofilms 1, n^o 1 (janvier 2004) : 13–19. http://dx.doi.org/10.1017/s1479050503001029.

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A fermentation system was designed to model the human colonic microflora in vitro. The system provided a framework of mucin beads to encourage the adhesion of bacteria, which was encased within a dialysis membrane. The void between the beads was inoculated with faeces from human donors. Water and metabolites were removed from the fermentation by osmosis using a solution of polyethylene glycol (PEG). The system was concomitantly inoculated alongside a conventional single-stage chemostat. Three fermentations were carried out using inocula from three healthy human donors.Bacterial populations from the chemostat and biofilm system were enumerated using fluorescence in situ hybridization. The culture fluid was also analysed for its short-chain fatty acid (SCFA) content. A higher cell density was achieved in the biofilm fermentation system (taking into account the contribution made by the bead-associated bacteria) as compared with the chemostat, owing to the removal of water and metabolites. Evaluation of the bacterial populations revealed that the biofilm system was able to support two distinct groups of bacteria: bacteria growing in association with the mucin beads and planktonic bacteria in the culture fluid. Furthermore, distinct differences were observed between populations in the biofilm fermenter system and the chemostat, with the former supporting higher populations of clostridia and Escherichia coli. SCFA levels were lower in the biofilm system than in the chemostat, as in the former they were removed via the osmotic effect of the PEG. These experiments demonstrated the potential usefulness of the biofilm system for investigating the complexity of the human colonic microflora and the contribution made by sessile bacterial populations.

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Jouët, P., J. M. Sabaté, B. Coffin, M. Lémann, R. Jian et B. Flourié. « Fermentation of starch stimulates propagated contractions in the human colon ». Neurogastroenterology & ; Motility 23, n^o 5 (28 décembre 2010) : 450—e176. http://dx.doi.org/10.1111/j.1365-2982.2010.01652.x.

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Cummings, J. H., et G. T. Macfarlane. « The control and consequences of bacterial fermentation in the human colon ». Journal of Applied Bacteriology 70, n^o 6 (juin 1991) : 443–59. http://dx.doi.org/10.1111/j.1365-2672.1991.tb02739.x.

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Macfarlane, G. T., G. R. Gibson et J. H. Cummings. « Comparison of fermentation reactions in different regions of the human colon ». Journal of Applied Bacteriology 72, n^o 1 (janvier 1992) : 57–64. http://dx.doi.org/10.1111/j.1365-2672.1992.tb04882.x.

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Macfarlane, G. T., G. R. Gibson et J. H. Cummings. « Comparison of fermentation reactions in different regions of the human colon ». Journal of Applied Microbiology 72, n^o 1 (janvier 1992) : 57–64. http://dx.doi.org/10.1111/j.1365-2672.1992.tb05187.x.

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Gibson, G. R., J. H. Cummings, G. T. Macfarlane, C. Allison, I. Segal, H. H. Vorster et A. R. Walker. « Alternative pathways for hydrogen disposal during fermentation in the human colon. » Gut 31, n^o 6 (1 juin 1990) : 679–83. http://dx.doi.org/10.1136/gut.31.6.679.

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Cummings, J. H., et H. N. Englyst. « Measurement of starch fermentation in the human large intestine ». Canadian Journal of Physiology and Pharmacology 69, n^o 1 (1 janvier 1991) : 121–29. http://dx.doi.org/10.1139/y91-018.

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Starch, not fibre, is probably the major substrate for fermentation in the human colon. However, quantitating the amount of starch that resists pancreatic amylase and thus escapes digestion in the small bowel is difficult. A number of techniques have been employed in man and are reviewed here, including direct intubation of the ileum, the ileostomy model, and breath studies. The results of a series of studies of the digestion of starch from potato and banana are reported. When fed to ileostomy patients, 3% of hot potato starch and 12% of cold potato starch were resistant to digestion, as was 75% of banana starch. In feeding experiments with healthy volunteers none of the starch was recoverable in faeces, indicating its complete fermentation in the colon. Breath H2 measurements after test meals of these starches indicated that only 2–5% of potato starch and 7–12% of banana starch was fermented. A single blood acetate measurement timed to coincide with peak breath H2 was not useful. However, a number of problems with breath H2 studies are discussed, and it is suggested that either ileal intubation or the ileostomy model are the most reliable techniques presently available, with serial blood acetate determinations also potentially valuable. Overall on Western diets, approximately 10% of all starch is probably resistant starch.Key words: starch, large intestine, fermentation, breath.

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Schlörmann, W., J. Atanasov, S. Lorkowski, C. Dawczynski et M. Glei. « Study on chemopreventive effects of raw and roasted β-glucan-rich waxy winter barley using an in vitro human colon digestion model ». Food & ; Function 11, n^o 3 (2020) : 2626–38. http://dx.doi.org/10.1039/c9fo03009c.

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Röytiö, H., et A. C. Ouwehand. « The fermentation of polydextrose in the large intestine and its beneficial effects ». Beneficial Microbes 5, n^o 3 (1 septembre 2014) : 305–13. http://dx.doi.org/10.3920/bm2013.0065.

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Polydextrose is a randomly bonded glucose polymer with a highly branched and complex structure. It resists digestion in the upper gastrointestinal tract and is partially fermented in the large intestine by the colonic microbes. Due to its complex structure, a plethora of microbes is required for the catabolism of polydextrose and this process occurs slowly. This gradual fermentation of polydextrose gives rise to moderate amounts of fermentation products, such as short chain fatty acids and gas. The production of these metabolites continues in the distal part of the colon, which is usually considered to be depleted of saccharolytic fermentation substrates. The fermentation of polydextrose modifies the composition of the microbiota in the colon, and has been shown to impact appetite and satiety in humans and improve the gastrointestinal function. The purpose of this short review is to summarise the in vitro, in vivo and human studies investigating the fermentation properties of polydextrose in the large intestine.

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Wolin, Meyer J., Terry L. Miller, Susan Yerry, Yongchao Zhang, Shelton Bank et Gary A. Weaver. « Changes of Fermentation Pathways of Fecal Microbial Communities Associated with a Drug Treatment That Increases Dietary Starch in the Human Colon ». Applied and Environmental Microbiology 65, n^o 7 (1 juillet 1999) : 2807–12. http://dx.doi.org/10.1128/aem.65.7.2807-2812.1999.

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ABSTRACT Acarbose inhibits starch digestion in the human small intestine. This increases the amount of starch available for microbial fermentation to acetate, propionate, and butyrate in the colon. Relatively large amounts of butyrate are produced from starch by colonic microbes. Colonic epithelial cells use butyrate as an energy source, and butyrate causes the differentiation of colon cancer cells. In this study we investigated whether colonic fermentation pathways changed during treatment with acarbose. We examined fermentations by fecal suspensions obtained from subjects who participated in an acarbose-placebo crossover trial. After incubation with [1-13C]glucose and 12CO2 or with unlabeled glucose and 13CO2, the distribution of 13C in product C atoms was determined by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. Regardless of the treatment, acetate, propionate, and butyrate were produced from pyruvate formed by the Embden-Meyerhof-Parnas pathway. Considerable amounts of acetate were also formed by the reduction of CO2. Butyrate formation from glucose increased and propionate formation decreased with acarbose treatment. Concomitantly, the amounts of CO2 reduced to acetate were 30% of the total acetate in untreated subjects and 17% of the total acetate in the treated subjects. The acetate, propionate, and butyrate concentrations were 57, 20, and 23% of the total final concentrations, respectively, for the untreated subjects and 57, 13, and 30% of the total final concentrations, respectively, for the treated subjects.

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Mannelli, Michele, Tania Gamberi, Francesca Magherini et Tania Fiaschi. « A Metabolic Change towards Fermentation Drives Cancer Cachexia in Myotubes ». Biomedicines 9, n^o 6 (20 juin 2021) : 698. http://dx.doi.org/10.3390/biomedicines9060698.

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Cachexia is a disorder associated with several pathologies, including cancer. In this paper, we describe how cachexia is induced in myotubes by a metabolic shift towards fermentation, and the block of this metabolic modification prevents the onset of the cachectic phenotype. Cachectic myotubes, obtained by the treatment with conditioned medium from murine colon carcinoma cells CT26, show increased glucose uptake, decreased oxygen consumption, altered mitochondria, and increased lactate production. Interestingly, the block of glycolysis by 2-deoxy-glucose or lactate dehydrogenase inhibition by oxamate prevents the induction of cachexia, thus suggesting that this metabolic change is greatly involved in cachexia activation. The treatment with 2-deoxy-glucose or oxamate induces positive effects also in mitochondria, where mitochondrial membrane potential and pyruvate dehydrogenase activity became similar to control myotubes. Moreover, in myotubes treated with interleukin-6, cachectic phenotype is associated with a fermentative metabolism, and the inhibition of lactate dehydrogenase by oxamate prevents cachectic features. The same results have been achieved by treating myotubes with conditioned media from human colon HCT116 and human pancreatic MIAPaCa-2 cancer cell lines, thus showing that what has been observed with murine-conditioned media is a wide phenomenon. These findings demonstrate that cachexia induction in myotubes is linked with a metabolic shift towards fermentation, and inhibition of lactate formation impedes cachexia and highlights lactate dehydrogenase as a possible new tool for counteracting the onset of this pathology.

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Stein, Katrin, Anke Borowicki, Daniel Scharlau, Anika Schettler, Kerstin Scheu, Ursula Obst et Michael Glei. « Effects of synbiotic fermentation products on primary chemoprevention in human colon cells ». Journal of Nutritional Biochemistry 23, n^o 7 (juillet 2012) : 777–84. http://dx.doi.org/10.1016/j.jnutbio.2011.03.022.

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Jouët, P., C. Gorbatchef, B. Flourié, B. Coffin, M. Lémann, C. Franchisseur, R. Jian et J. C. Rambaud. « Colonic fermentation of lactulose produces a tonic contraction in the human colon ». Gastroenterology 114 (avril 1998) : A773. http://dx.doi.org/10.1016/s0016-5085(98)83161-2.

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Mäkeläinen, H., S. Forssten, M. Saarinen, J. Stowell, N. Rautonen et A. Ouwehand. « Xylo-oligosaccharides enhance the growth of bifidobacteria and Bifidobacterium lactis in a simulated colon model ». Beneficial Microbes 1, n^o 1 (1 mars 2010) : 81–91. http://dx.doi.org/10.3920/bm2009.0025.

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A semi-continuous, anaerobic colon simulator, with four vessels mimicking the conditions of the human large intestine, was used to study the fermentation of xylo-oligosaccharides (XOS). Three XOS compounds and a xylan preparation were fermented for 48 hours by human colonic microbes. Fructo-oligosaccharides (FOS) were used as a prebiotic reference. As a result of the fermentation, the numbers of Bifidobacterium increased in all XOS and xylan simulations when compared to the growth observed in the baseline simulations, and increased levels of Bifidobacterium lactis were measured with the two XOS compounds that had larger distribution of the degree of polymerisation. Fermentation of XOS and xylan increased the microbial production of short chain fatty acids in the simulator vessels; especially the amounts of butyrate and acetate were increased. XOS was more efficient than FOS in increasing the numbers of B. lactis in the colonic model, whereas FOS increased the Bifidobacterium longum numbers more. The selective fermentation of XOS by B. lactis has been demonstrated in pure culture studies, and these results further indicate that the combination of B. lactis and XOS would form a successful, selective synbiotic combination.

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Borowicki, Anke, Katrin Stein, Daniel Scharlau, Kerstin Scheu, Gerald Brenner-Weiss, Ursula Obst, Jürgen Hollmann, Meinolf Lindhauer, Norbert Wachter et Michael Glei. « Fermented wheat aleurone inhibits growth and induces apoptosis in human HT29 colon adenocarcinoma cells ». British Journal of Nutrition 103, n^o 3 (7 septembre 2009) : 360–69. http://dx.doi.org/10.1017/s0007114509991899.

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Fermentation of dietary fibre by the gut microflora may enhance levels of SCFA, which are potentially chemoprotective against colon cancer. Functional food containing wheat aleurone may prevent cancer by influencing cell cycle and cell death. We investigated effects of fermented wheat aleurone on growth and apoptosis of HT29 cells. Wheat aleurone, flour and bran were digested and fermentedin vitro. The resulting fermentation supernatants (fs) were analysed for their major metabolites (SCFA, bile acids and ammonia). HT29 cells were treated for 24–72 h with the fs or synthetic mixtures mimicking the fs in SCFA, butyrate or deoxycholic acid (DCA) contents, and the influence on cell growth was determined. Fs aleurone was used to investigate the modulation of apoptosis and cell cycle. The fermented wheat samples contained two- to threefold higher amounts of SCFA than the faeces control (blank), but reduced levels of bile acids and increased concentrations of ammonia. Fs aleurone and flour equally reduced cell growth of HT29 more effectively than the corresponding blank and the SCFA mixtures. The EC50(48 h) ranged from 10 % (flour) to 19 % (blank). Markedly after 48 h, fs aleurone (10 %) significantly induced apoptosis and inhibited cell proliferation by arresting the cell cycle in the G0/G1 phase. In conclusion, fermentation of wheat aleurone results in a reduced level of tumour-promoting DCA, but higher levels of potentially chemopreventive SCFA. Fermented wheat aleurone is able to induce apoptosis and to block cell cycle – two essential markers of secondary chemoprevention.

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Martínez-López, Ana L., Elizabeth Carvajal-Millan, Rafael Canett-Romero, Satya Prakash, Agustín Rascón-Chu, Yolanda L. López-Franco, Jaime Lizardi-Mendoza et Valerie Micard. « Arabinoxylans-Based Oral Insulin Delivery System Targeting the Colon : Simulation in a Human Intestinal Microbial Ecosystem and Evaluation in Diabetic Rats ». Pharmaceuticals 15, n^o 9 (26 août 2022) : 1062. http://dx.doi.org/10.3390/ph15091062.

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Arabinoxylans (AX) microcapsules loaded with insulin were prepared by enzymatic gelation of AX, using a triaxial electrospray method. The microcapsules presented a spherical shape, with an average size of 250 µm. The behavior of AX microcapsules was evaluated using a simulator of the human intestinal microbial ecosystem. AX microcapsules were mainly (70%) degraded in the ascending colon. The fermentation was completed in the descending colon, increasing the production of acetic, propionic, and butyric acids. In the three regions of the colon, the fermentation of AX microcapsules significantly increased populations of Bifidobacterium and Lactobacillus and decreased the population of Enterobacteriaceae. In addition, the results found in this in vitro model showed that the AX microcapsules could resist the simulated conditions of the upper gastrointestinal system and be a carrier for insulin delivery to the colon. The pharmacological activity of insulin-loaded AX microcapsules was evaluated after oral delivery in diabetic rats. AX microcapsules lowered the serum glucose levels in diabetic rats by 75%, with insulin doses of 25 and 50 IU/kg. The hypoglycemic effect and the insulin levels remained for more than 48 h. Oral relative bioavailability was 13 and 8.7% for the 25 and 50 IU/kg doses, respectively. These results indicate that AX microcapsules are a promising microbiota-activated system for oral insulin delivery in the colon.

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McBurney, Michael I. « Passage of starch into the colon of humans : quantitation and implications ». Canadian Journal of Physiology and Pharmacology 69, n^o 1 (1 janvier 1991) : 130–36. http://dx.doi.org/10.1139/y91-019.

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It has been suggested that a significant amount of starch may reach the colon undigested and stimulate microbial fermentation. Indirect estimates of the quantity of starch reaching the colon have been obtained from breath hydrogen (H2) measurements, but numerous variables, i.e., dietary fiber source and level of intake, oral hygiene, hyperventilation, and cigarette smoking, stimulate H2 production and may exaggerate estimates of starch malabsorption. With proper controls, however, the lactulose breath H2 test based on total excess volume seems to provide a reasonable measure of the average amount of starch metabolized in the colon. Direct estimates of starch metabolism from human ileostomy studies suggest that typically < 5% of the ingested starch escapes digestion in the small intestine. The general assumption that starch malabsorption stimulates normal colonic function, particularly with respect to colorectal carcinogenesis, is not entirely supported by the limited number of available epidemiologic studies. Further experimental studies are needed to elucidate the role of starch intake and malabsorption on colonic function and human health issues.Key words: starch, malabsorption, colonic fermentation, carcinogenesis, large bowel.

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Costabile, Adele, Francesca Fava, Henna Röytiö, Sofia D. Forssten, Kaisa Olli, Judith Klievink, Ian R. Rowland et al. « Impact of polydextrose on the faecal microbiota : a double-blind, crossover, placebo-controlled feeding study in healthy human subjects ». British Journal of Nutrition 108, n^o 3 (21 novembre 2011) : 471–81. http://dx.doi.org/10.1017/s0007114511005782.

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In this placebo-controlled, double-blind, crossover human feeding study, the effects of polydextrose (PDX; 8 g/d) on the colonic microbial composition, immune parameters, bowel habits and quality of life were investigated. PDX is a complex glucose oligomer used as a sugar replacer. The main goal of the present study was to identify the microbial groups affected by PDX fermentation in the colon. PDX was shown to significantly increase the known butyrate producerRuminococcus intestinalisand bacteria of theClostridiumclusters I, II and IV. Of the other microbial groups investigated, decreases in the faecalLactobacillus–Enterococcusgroup were demonstrated. Denaturing gel gradient electrophoresis analysis showed that bacterial profiles between PDX and placebo treatments were significantly different. PDX was shown to be slowly degraded in the colon, and the fermentation significantly reduced the genotoxicity of the faecal water. PDX also affected bowel habits of the subjects, as less abdominal discomfort was recorded and there was a trend for less hard and more formed stools during PDX consumption. Furthermore, reduced snacking was observed upon PDX consumption. This study demonstrated the impact of PDX on the colonic microbiota and showed some potential for reducing the risk factors that may be associated with colon cancer initiation.

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Munjal, Umang, Michael Glei, Beatrice Louise Pool-Zobel et Daniel Scharlau. « Fermentation products of inulin-type fructans reduce proliferation and induce apoptosis in human colon tumour cells of different stages of carcinogenesis ». British Journal of Nutrition 102, n^o 5 (14 septembre 2009) : 663–71. http://dx.doi.org/10.1017/s0007114509274770.

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Epidemiological evidence suggests that the intake of prebiotic dietary fibres, for example, inulin, protects against colorectal cancer. However, little is known about cellular responses to complex fermentation samples. Therefore, we prepared a fermentation supernatant fraction of inulin and studied biological properties in human colon cell lines, LT97 and HT29 (representing early and late stages of colon cancer). Inulin enriched with oligofructose (Synergy 1) was incubated under anaerobic conditions with faecal inocula and the supernatant fraction was characterised for content of SCFA and secondary bile acid deoxycholic acid (DCA). A Synergy fermentation supernatant fraction (SFS) and a synthetic fermentation mixture (SFM) mimicking the SFS in SCFA and DCA content were used in the concentration range of 1·25–20 % (v/v) for 24–72 h. The effects on cell growth were determined by quantifying DNA. Effects on apoptosis were analysed by measuring poly(ADP-ribose) polymerase (PARP) cleavage using Western blotting. Compared with the faecal blank, produced without the addition of inulin, the SFS resulted in an almost 2·5-fold increase of SCFA and 3·4-fold decrease of DCA. In comparison with HT29 cells, LT97 cells responded more sensitively to the growth-inhibitory activities. Additionally, a significant increase in PARP cleavage was observed in LT97 cells after incubation with the SFS, demonstrating induction of apoptosis. The present results indicate growth-inhibiting and apoptosis-inducing effects of fermentation supernatant fractions of inulin. Moreover, since early adenoma cells were found to be more sensitive, this may have important implications for chemoprevention when translated to the in vivo situation, because survival of early transformed cells could be reduced.

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Pool-Zobel, Beatrice L. « Inulin-type fructans and reduction in colon cancer risk : review of experimental and human data ». British Journal of Nutrition 93, S1 (avril 2005) : S73—S90. http://dx.doi.org/10.1079/bjn20041349.

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Inulin-type fructans (β(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 APCMin 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.

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Jarosova, Veronika, Ondrej Vesely, Petr Marsik, Jose Jaimes, Karel Smejkal, Pavel Kloucek et Jaroslav Havlik. « Metabolism of Stilbenoids by Human Faecal Microbiota ». Molecules 24, n^o 6 (23 mars 2019) : 1155. http://dx.doi.org/10.3390/molecules24061155.

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Stilbenoids are dietary phenolics with notable biological effects on humans. Epidemiological, clinical, and nutritional studies from recent years have confirmed the significant biological effects of stilbenoids, such as oxidative stress protection and the prevention of degenerative diseases, including cancer, cardiovascular diseases, and neurodegenerative diseases. Stilbenoids are intensively metabolically transformed by colon microbiota, and their corresponding metabolites might show different or stronger biological activity than their parent molecules. The aim of the present study was to determine the metabolism of six stilbenoids (resveratrol, oxyresveratrol, piceatannol, thunalbene, batatasin III, and pinostilbene), mediated by colon microbiota. Stilbenoids were fermented in an in vitro faecal fermentation system using fresh faeces from five different donors as an inoculum. The samples of metabolized stilbenoids were collected at 0, 2, 4, 8, 24, and 48 h. Significant differences in the microbial transformation among stilbene derivatives were observed by liquid chromatography mass spectrometry (LC/MS). Four stilbenoids (resveratrol, oxyresveratrol, piceatannol and thunalbene) were metabolically transformed by double bond reduction, dihydroxylation, and demethylation, while batatasin III and pinostilbene were stable under conditions simulating the colon environment. Strong inter-individual differences in speed, intensity, and pathways of metabolism were observed among the faecal samples obtained from the donors.

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WATKINS, STEVEN M., LYNNE C. CARTER, JEANNIE MAK, JAMES TSAU, SHERYL YAMAMOTO et J. BRUCE GERMAN. « Butyric acid and tributyrin induce apoptosis in human hepatic tumour cells ». Journal of Dairy Research 66, n^o 4 (novembre 1999) : 559–67. http://dx.doi.org/10.1017/s0022029999003830.

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The anti-colon cancer effect of dietary fibre results in part from its fermentation into the short-chain fatty acid butyric acid (BA) by intestinal microflora. BA has potent anti-colon cancer properties owing to its ability to induce apoptosis in colon cancer cells. The colon is not the only location where BA may reach high concentrations, because dietary BA is rapidly absorbed and transported to the liver. We have investigated whether BA could induce apoptosis in transformed human liver (Hep G2) cells. Hep G2 cells treated with BA displayed acetylated histones, increased DNA fragmentation and morphological features consistent with apoptosis. These biochemical features of BA-treated liver cells are identical to those of BA-treated colon cells. In addition, we investigated whether BA present in tributyrin, a triacylglycerol more compatible for inclusion into colloidal lipid structures than BA, could also induce apoptosis in Hep G2 cells. Tributyrin induced DNA fragmentation and morphological features characteristic of apoptotic cells in Hep G2 cells. These results are a significant advance towards delivering BA via colloidal lipid particles to cancerous sites in vivo. This study showed that BA and tributyrin are potent apoptotic agents, and we suggest that sources of dietary BA, such as milk fat, may provide anti-liver cancer properties.

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Sonoyama, Kei, Pimara Pholnukulkit, Masahiko Toyoda, Suriya Rutatip et Takanori Kasai. « Upregulation of activin A gene by butyrate in human colon cancer cell lines ». American Journal of Physiology-Gastrointestinal and Liver Physiology 284, n^o 6 (1 juin 2003) : G989—G995. http://dx.doi.org/10.1152/ajpgi.00384.2002.

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Activin A has been reported to play a role in the progression of colorectal cancer. Because dietary fiber protects against colorectal cancer, we hypothesized that butyrate, a fermentation product of dietary fiber, may affect the expression of activin A in colon cancer cells. Semiquantitative RT-PCR demonstrated that the activin A gene was upregulated by sodium butyrate in the human colon cancer cell lines HT-29 and Caco-2 in a concentration- and time-dependent manner. However, the activin A gene did not respond to sodium butyrate in the human normal colonic cell line FHC, rat normal intestinal epithelial cell (IEC) line IEC-6, and the explant of rat colon. Flow cytometry and agarose gel electrophoresis of genomic DNA revealed that cell cycle arrest and apoptosis were induced by sodium butyrate but not exogenous activin A in HT-29 cells, indicating that activin A could not act as an autocrine factor in colon cancer cells. By assuming that activin A promotes colorectal cancer spread as a paracrine factor, our findings suggest that butyrate could act as a tumor promoter in some circumstances.

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Ács, Norbert, Ross Holohan, Laura J. Dunne, Adrian R. Fernandes, Adam G. Clooney, Lorraine A. Draper, R. Paul Ross et Colin Hill. « Comparing In Vitro Faecal Fermentation Methods as Surrogates for Phage Therapy Application ». Viruses 14, n^o 12 (25 novembre 2022) : 2632. http://dx.doi.org/10.3390/v14122632.

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The human microbiome and its importance in health and disease have been the subject of numerous research articles. Most microbes reside in the digestive tract, with up to 1012 cells per gram of faecal material found in the colon. In terms of gene number, it has been estimated that the gut microbiome harbours >100 times more genes than the human genome. Several human intestinal diseases are strongly associated with disruptions in gut microbiome composition. Less studied components of the gut microbiome are the bacterial viruses called bacteriophages that may be present in numbers equal to or greater than the prokaryotes. Their potential to lyse their bacterial hosts, or to act as agents of horizontal gene transfer makes them important research targets. In this study in vitro faecal fermentation systems were developed and compared for their ability to act as surrogates for the human colon. Changes in bacterial and viral composition occurred after introducing a high-titre single phage preparation both with and without a known bacterial host during the 24 h-long fermentation. We also show that during this timeframe 50 mL plastic tubes can provide data similar to that generated in a sophisticated faecal fermenter system. This knowledge can guide us to a better understanding of the short-term impact of bacteriophage transplants on the bacteriomes and viromes of human recipients.

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Goya-Jorge, Elizabeth, Irma Gonza, Pauline Bondue, Caroline Douny, Bernard Taminiau, Georges Daube, Marie-Louise Scippo et Véronique Delcenserie. « Human Adult Microbiota in a Static Colon Model : AhR Transcriptional Activity at the Crossroads of Host–Microbe Interaction ». Foods 11, n^o 13 (30 juin 2022) : 1946. http://dx.doi.org/10.3390/foods11131946.

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Functional symbiotic intestinal microbiota regulates immune defense and the metabolic processing of xenobiotics in the host. The aryl hydrocarbon receptor (AhR) is one of the transcription factors mediating host–microbe interaction. An in vitro static simulation of the human colon was used in this work to analyze the evolution of bacterial populations, the microbial metabolic output, and the potential induction of AhR transcriptional activity in healthy gut ecosystems. Fifteen target taxa were explored by qPCR, and the metabolic content was chromatographically profiled using SPME-GC-MS and UPLC-FLD to quantify short-chain fatty acids (SCFA) and biogenic amines, respectively. Over 72 h of fermentation, the microbiota and most produced metabolites remained stable. Fermentation supernatant induced AhR transcription in two of the three reporter gene cell lines (T47D, HepG2, HT29) evaluated. Mammary and intestinal cells were more sensitive to microbiota metabolic production, which showed greater AhR agonism than the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) used as a positive control. Some of the SCFA and biogenic amines identified could crucially contribute to the potent AhR induction of the fermentation products. As a fundamental pathway mediating human intestinal homeostasis and as a sensor for several microbial metabolites, AhR activation might be a useful endpoint to include in studies of the gut microbiota.

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Vieira Teixeira da Silva, Davi, Diego dos Santos Baião, Fabrício de Oliveira Silva, Genilton Alves, Daniel Perrone, Eduardo Mere Del Aguila et Vania M. Flosi Paschoalin. « Betanin, a Natural Food Additive : Stability, Bioavailability, Antioxidant and Preservative Ability Assessments ». Molecules 24, n^o 3 (28 janvier 2019) : 458. http://dx.doi.org/10.3390/molecules24030458.

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Betanin is the only betalain approved for use in food and pharmaceutical products as a natural red colorant. However, the antioxidant power and health-promoting properties of this pigment have been disregarded, perhaps due to the difficulty in obtaining a stable chemical compound, which impairs its absorption and metabolism evaluation. Herein, betanin was purified by semi-preparative HPLC-LC/MS and identified by LC-ESI(+)-MS/MS as the pseudomolecular ion m/z 551.16. Betanin showed significant stability up to −30 °C and mild stability at chilling temperature. The stability and antioxidant ability of this compound were assessed during a human digestion simulation and ex vivo colon fermentation. Half of the betanin amount was recovered in the small intestine digestive fluid and no traces were found after colon fermentation. Betanin high antioxidant ability was retained even after simulated small intestine digestion. Betanin, besides displaying an inherent colorant capacity, was equally effective as a natural antioxidant displaying peroxy-radical scavenger ability in pork meat. Betanin should be considered a multi-functional molecule able to confer an attractive color to frozen or refrigerated foods, but with the capacity to avoid lipid oxidation, thereby preserving food quality. Long-term supplementation by beetroot, a rich source of betanin, should be stimulated to protect organisms against oxidative stress.

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Anshory, Muhammad, Raden Mohamad Rendy Ariezal Effendi, Handono Kalim, Reiva Farah Dwiyana, Oki Suwarsa, Tamar E. C. Nijsten, Jan L. Nouwen et Hok Bing Thio. « Butyrate Properties in Immune-Related Diseases : Friend or Foe ? » Fermentation 9, n^o 3 (21 février 2023) : 205. http://dx.doi.org/10.3390/fermentation9030205.

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Butyrate is a short-chain fatty acid (SCFA) created within the intestinal lumen by bacterial fermentation of largely undigested dietary carbohydrates. Its beneficial effects on cellular energy metabolism and intestinal homeostasis have garnered significant attention among SCFAs. Butyrate also has systemic effects and is known to regulate the immune system. Most of the butyrate and other SCFAs are produced in the human colon, through the fermentation of dietary fiber or resistant starch. However, the modern diet often lacks sufficient intake of fermentable dietary fiber, which can lead to low butyrate levels in the colon. To increase butyrate levels, it is helpful to incorporate fiber sources into meals and drinks that rely on slow bacterial fermentation. Butyrate is well known for its anti-inflammatory properties and has a range of immune system-related properties. As an agonist for GPR41, GPR43, or GPR109A, butyrate may have anti-inflammatory effects through these receptors’ signaling pathways. Butyrate also serves as an epigenetic regulator, responding to environmental or pharmacological changes by inhibiting HDAC, up-regulating miR-7a-5p, and promoting histone butyrylation and autophagy processes. This review discusses the importance of butyrate in regulating immunological homeostasis and the inflammatory response. It also addresses experimental models and human studies investigating the therapeutic potential of butyrate supplementation in immune-related conditions linked to butyrate depletion. Specifically, it covers the role of butyrate in some immune-related diseases such as systemic lupus erythematosus, atopic dermatitis, psoriasis, human immunodeficiency virus, cancer, and several other special conditions.

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Scheppach, Wolfgang, Hardi Luehrs et Thomas Menzel. « Beneficial health effects of low-digestible carbohydrate consumption ». British Journal of Nutrition 85, S1 (mars 2001) : S23—S30. http://dx.doi.org/10.1079/bjn2000259.

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Low-digestible carbohydrates represent a class of enzyme-resistant saccharides that have specific effects on the human gastrointestinal tract. In the small bowel, they affect nutrient digestion and absorption, glucose and lipid metabolism and protect against known risk factors of cardiovascular disease. In the colon they are mainly degraded by anaerobic bacteria in a process called fermentation. As a consequence, faecal nitrogen excretion is enhanced, which is used clinically to prevent or treat hepatic encephalopathy. Low-digestible carbohydrates are trophic to the epithelia of the ileum and colon, which helps to avoid bacterial translocation. Short-chain fatty acids are important fermentation products and are evaluated as new therapeutics in acute colitis. They are considered in the primary prevention of colorectal cancer. The bifidogenic effect of fructo-oligosaccharides merits further attention. Unfermented carbohydrates increase faecal bulk and play a role in the treatment of chronic functional constipation, symptomatic diverticulosis and, possibly, the irritable bowel syndrome. In conclusion, low-digestible carbohydrates may play a role in the maintenance of human digestive health. However, the strength of evidence differs between disease entities.

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Viljoen, M., et A. Koorts. « Prebiotics : selective substrate for beneficial microflora ». Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 24, n^o 1/2 (22 septembre 2005) : 11–16. http://dx.doi.org/10.4102/satnt.v24i1/2.163.

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Prebiotics are food ingredients that are not digested by the host’s digestive enzymes. Prebiotics are fermented in the colon under influence of colon bacteria such as bifidobacteria. It serves as selective substrate for those microflora that benefit the host and simultaneously increases the fermentation capacity of the colon. Oligosaccharides are the best general prebiotics as they stimulate the growth and colonisation of beneficial bacteria such as bifidobacteria and their metabolites are not toxic. Common examples of prebiotics include fructooligosaccharides (FOS), galactooligosaccharides (GOS) and soybean oligosaccharides. The prebiotic-probiotic-host cell interaction plays a role in the integrity of the gastrointestinal tract, the mucosal immune system, the absorption of minerals and other aspects of the human physiology.

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Pomare, E. W., W. J. Branch et J. H. Cummings. « Carbohydrate fermentation in the human colon and its relation to acetate concentrations in venous blood. » Journal of Clinical Investigation 75, n^o 5 (1 mai 1985) : 1448–54. http://dx.doi.org/10.1172/jci111847.

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Tornero-Martínez, Antonio, Rubén Cruz-Ortiz, María Eugenia Jaramillo-Flores, Perla Osorio-Díaz, Sandra Victoria Ávila-Reyes, Guadalupe Monserrat Alvarado-Jasso et Rosalva Mora-Escobedo. « In vitro Fermentation of Polysaccharides from Aloe vera and the Evaluation of Antioxidant Activity and Production of Short Chain Fatty Acids ». Molecules 24, n^o 19 (7 octobre 2019) : 3605. http://dx.doi.org/10.3390/molecules24193605.

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Soluble or fermentable fibre has prebiotic effects that can be used in the food industry to modify the composition of microbiota species to benefit human health. Prebiotics mostly target Bifidobacterium and Lactobacillus strains, among others, which can fight against chronic diseases since colonic fermentation produces short chain fatty acids (SCFAs). The present work studied the changes produced in the fibre and polyphenolic compounds during in vitro digestion of gel (AV) and a polysaccharide extract (AP) from Aloe vera, after which, these fractions were subjected to in vitro colonic fermentation to evaluate the changes in antioxidant capacity and SCFAs production during the fermentation. The results showed that the phenolic compounds increased during digestion, but were reduced in fermentation, as a consequence, the antioxidant activity increased significantly in AV and AP after the digestion. On the other hand, during in vitro colon fermentation, the unfermented fibre of AV and AP responded as lactulose and the total volume of gas produced, which indicates the possible use of Aloe vera and polysaccharide extract as prebiotics.

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Duncan, Sylvia H., Petra Louis et Harry J. Flint. « Lactate-Utilizing Bacteria, Isolated from Human Feces, That Produce Butyrate as a Major Fermentation Product ». Applied and Environmental Microbiology 70, n^o 10 (octobre 2004) : 5810–17. http://dx.doi.org/10.1128/aem.70.10.5810-5817.2004.

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ABSTRACT The microbial community of the human colon contains many bacteria that produce lactic acid, but lactate is normally detected only at low concentrations (<5 mM) in feces from healthy individuals. It is not clear, however, which bacteria are mainly responsible for lactate utilization in the human colon. Here, bacteria able to utilize lactate and produce butyrate were identified among isolates obtained from 10−8 dilutions of fecal samples from five different subjects. Out of nine such strains identified, four were found to be related to Eubacterium hallii and two to Anaerostipes caccae, while the remaining three represent a new species within clostridial cluster XIVa based on their 16S rRNA sequences. Significant ability to utilize lactate was not detected in the butyrate-producing species Roseburia intestinalis, Eubacterium rectale, or Faecalibacterium prausnitzii. Whereas E. hallii and A. caccae strains used both d- and l-lactate, the remaining strains used only the d form. Addition of glucose to batch cultures prevented lactate utilization until the glucose became exhausted. However, when two E. hallii strains and one A. caccae strain were grown in separate cocultures with a starch-utilizing Bifidobacterium adolescentis isolate, with starch as the carbohydrate energy source, the l-lactate produced by B. adolescentis became undetectable and butyrate was formed. Such cross-feeding may help to explain the reported butyrogenic effect of certain dietary substrates, including resistant starch. The abundance of E. hallii in particular in the colonic ecosystem suggests that these bacteria play important roles in preventing lactate accumulation.

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Borowicki, Anke, Katrin Stein, Daniel Scharlau et Michael Glei. « Fermentation Supernatants of Wheat (Triticum aestivum L.) Aleurone Beneficially Modulate Cancer Progression in Human Colon Cells ». Journal of Agricultural and Food Chemistry 58, n^o 3 (10 février 2010) : 2001–7. http://dx.doi.org/10.1021/jf9032848.

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Feria-Gervasio, David, Sylvain Denis, Monique Alric et Jean-François Brugère. « In vitro maintenance of a human proximal colon microbiota using the continuous fermentation system P-ECSIM ». Applied Microbiology and Biotechnology 91, n^o 5 (20 juillet 2011) : 1425–33. http://dx.doi.org/10.1007/s00253-011-3462-5.

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Alles, Martine S., Joseph G. A. J. Hautvast, Fokko M. Nagengast, Ralf Hartemink, Katrien M. J. Van Laere et Jan B. M. J. Jansen. « Fate of fructo-oligosaccharides in the human intestine ». British Journal of Nutrition 76, n^o 2 (août 1996) : 211–21. http://dx.doi.org/10.1079/bjn19960026.

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There is a need for studies on colonic fermentation in order to learn more abouthealth and diseases of the colon. The aim of the present study was to evaluate the fate of twodifferent doses of fructo-oligosaccharides (5 and 15 g/d) v. glucose in the intestine of healthy men. Twenty-four volunteers participated in a 5-weekstudy. The study was a completely balanced multiple crossover trial using an orthogonal Latin-square design for three periods, with supplement periods of 7 d and two 7 d wash-out periods. Breath samples and faecal samples were collected. There was a clear gaseous response to the consumption of fructo-oligosaccharides. The highest dose significantly increased 24 h integratedexcretion of breath H2 (P < 0·05). Breath H2 excretion after ingestion of 5 g fructo-oligosaccharides was higher than control, but did not reach significance. No effects on the total concentration of short-chain fatty acids in faeces were observed, no modification of the molar proportions of the various short-chain fatty acids was observed. The faecal pH did not change. No changes in faecal weight were observed. No fructo-oligosaccharides were recovered in faeces. We conclude that fructo-oligosaccharides added to the diet of young Western subjects are fully metabolized in the large intestine. The level of fermentation seems to be dose-dependent.

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Rose, Devin J., Koen Venema, Ali Keshavarzian et Bruce R. Hamaker. « Starch-entrapped microspheres show a beneficial fermentation profile and decrease in potentially harmful bacteria duringin vitrofermentation in faecal microbiota obtained from patients with inflammatory bowel disease ». British Journal of Nutrition 103, n^o 10 (21 décembre 2009) : 1514–24. http://dx.doi.org/10.1017/s0007114509993515.

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The purpose of this research was to test the hypothesis that starch-entrapped microspheres would produce favourable fermentation profiles and microbial shifts duringin vitrofermentation with the faecal microbiota from patients with inflammatory bowel disease (IBD).In vitrofermentation was carried out using a validated, dynamic, computer-controlled model of the human colon (Toegepast Natuurwetenschappelijk Onderzoek gastro-intestinal model-2) after inoculation with pooled faeces from healthy individuals, patients with inactive IBD (Crohn's disease (CD)) or patients with active IBD (ulcerative colitis (UC)). Starch-entrapped microspheres fermented more slowly and produced more butyrate than fructo-oligosaccharides (FOS) when fermented with the faecal microbiota from patients with active UC. When fermented with the microbiota from patients with inactive CD, starch-entrapped microspheres also fermented more slowly but produced similar amounts of butyrate compared with FOS. Starch-entrapped microspheres showed a greater ability to maintain a low pH during simulated-distal colon conditions compared with FOS. After fermentation with the microbiota from inactive CD patients, starch-entrapped microspheres resulted in lower concentrations of some potentially harmful gut bacteria, included inBacteroides,Enterococcus,FusobacteriumandVeillonella, compared with FOS. These findings suggest that slow fermenting starch-entrapped microspheres may induce a favourable colonic environment in patients with IBD through high butyrate production, maintenance of low pH in the distal colon and inhibition of the growth of potentially harmful bacteria.

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Probert, Hollie M., Juha H. A. Apajalahti, Nina Rautonen, Julian Stowell et Glenn R. Gibson. « Polydextrose, Lactitol, and Fructo-Oligosaccharide Fermentation by Colonic Bacteria in a Three-Stage Continuous Culture System ». Applied and Environmental Microbiology 70, n^o 8 (août 2004) : 4505–11. http://dx.doi.org/10.1128/aem.70.8.4505-4511.2004.

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ABSTRACT In vitro fermentations were carried out by using a model of the human colon to simulate microbial activities of lower gut bacteria. Bacterial populations (and their metabolic products) were evaluated under the effects of various fermentable substrates. Carbohydrates tested were polydextrose, lactitol, and fructo-oligosaccharide (FOS). Bacterial groups of interest were evaluated by fluorescence in situ hybridization as well as by species-specific PCR to determine bifidobacterial species and percent-G+C profiling of the bacterial communities present. Short-chain fatty acids (SCFA) produced during the fermentations were also evaluated. Polydextrose had a stimulatory effect upon colonic bifidobacteria at concentrations of 1 and 2% (using a single and pooled human fecal inoculum, respectively). The bifidogenic effect was sustained throughout all three vessels of the in vitro system (P = 0.01 seen in vessel 3), as corroborated by the bacterial community profile revealed by %G+C analysis. This substrate supported a wide variety of bifidobacteria and was the only substrate where Bifidobacterium infantis was detected. The fermentation of lactitol had a deleterious effect on both bifidobacterial and bacteroides populations (P = 0.01) and decreased total cell numbers. SCFA production was stimulated, however, particularly butyrate (beneficial for host colonocytes). FOS also had a stimulatory effect upon bifidobacterial and lactobacilli populations that used a single inoculum (P = 0.01 for all vessels) as well as a bifidogenic effect in vessels 2 and 3 (P = 0.01) when a pooled inoculum was used. A decrease in bifidobacteria throughout the model was reflected in the percent-G+C profiles.

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Sivieri, Katia, Fernanda Bianchi, Maria A. Tallarico et Elizeu A. Rossi. « Fermentation by gut microbiota cultured in a simulator of the human intestinal microbial ecosystem is improved by probiotic Enterococcus faecium CRL 183 ». Functional Foods in Health and Disease 1, n^o 10 (8 octobre 2011) : 389. http://dx.doi.org/10.31989/ffhd.v1i10.119.

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Background: Enterococci are used in a large number of dairy products, such as starter cultures in food supplements and in foods considered functional. In vitro gut fermentation models present an unmatched opportunity of performing studies frequently allenged in humans and animals owing to ethical concerns. A dynamic model of the human intestinal microbial ecosystem (SHIME) was designed to better simulate conditions intestinal microbiota.Methods: The SHIME model was used to study the effect of Enterococuus faecium CRL 183 on the fermentation pattern of the colon microbiota. Initially, an inoculum prepared from human feces was introduced into the reactor vessels and stabilized over 2 wk using a culture medium. This stabilization period was followed by a 2-wk control period during which the microbiota were monitored. The microbiota were then subjected to a 4-wk treatment period by adding 108 CFU/mL of the Enterococcus faecium CRL 183 to vessel one (the stomach compartment).Results: The addition resulted into an overall increase of bacterial marker populations (Enterobacteriaceae, Lactobacillus spp., Bifidobacterium spp. and Clostridium spp.), with a significant increase of the Lactobacillus sp. and Bifidobacterium sp populations. The short-chain fatty acid (SCFA) concentration increased during the supplementation period; this was due mainly to a significant increase in the levels of acetic, butyric and propionic acids. Ammonium concentrations increased during the supplementation period.Conclusions: Results showed that the major effect of E. faecium CRL 183 was found in the ascendant and transverse colon. Key words: Gut microbiota, Enterococcus, Gastrointestinal resource management, Simulator of Human Intestinal Microbial Ecosystem (SHIME)

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Nielsen, Ditte Søvsø Gundelund, Bent Borg Jensen, Peter Kappel Theil, Tina Skau Nielsen, Knud Erik Bach Knudsen et Stig Purup. « Effect of butyrate and fermentation products on epithelial integrity in a mucus-secreting human colon cell line ». Journal of Functional Foods 40 (janvier 2018) : 9–17. http://dx.doi.org/10.1016/j.jff.2017.10.023.

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Gribakin, S. G., S. V. Orlova et I. V. Podoprigora. « Development and role of intestinal microbiota in term and preterm newborn babies. Accent on breast feeding ». Medical alphabet, n^o 16 (1 septembre 2022) : 44–50. http://dx.doi.org/10.33667/2078-5631-2022-16-44-50.

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Intestinal microbiota (IM) plays in human organism a number of various functions including a participation in metabolic procecces, stimulation of immune function, competition with pathogenic flora, fermentation activity in colon. Microbial colonization of sterile gastrointestinal tract of newborn is based on several natural principles and depends on mode of delivery, vaginal and fecal flora of own mother, external factors (hospitalization, antibiotic therapy), and as well is regulated by breast feeding or bottle feeding. Besides that there is a proven difference between term and preterm newborn babies. Microbial community (so called Microbiome) of human milk with its complicated microbial society plays a key role in IM development, especially in combination with human milk oligosaccharides evolutionary connected with human intestinal microbiota development.

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Larder, Christina E., Michèle M. Iskandar et Stan Kubow. « Dynamic Multi-Stage Gastrointestinal Digestion Model Assessment of Microbial Fermentation Products of Collagen Hydrolysates ». Proceedings 61, n^o 1 (30 octobre 2020) : 12. http://dx.doi.org/10.3390/iecn2020-06998.

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Proteins, peptides and amino acids (AAs) that bypass upper gastrointestinal (GI) digestion can be fermented in the colonic regions. This could lead to microbial production of health promoting short-chain fatty acids (SCFAs). Nitrogenous compounds can also be fermented to generate potentially harmful branched chain fatty acids (BCFAs). As collagen hydrolysate (CH) supplements contain a high peptide content, we evaluated whether peptides that undergo intestinal CH digestion and microbial fermentation can generate SCFAs and BCFAs. Two bovine-sourced CH formulations (CH-GL and CH-OPT) underwent digestive processes and microbial fermentation for 24 h in a dynamic GI digestion model containing human fecal matter. After 24 h, CH-OPT showed a significant (p < 0.05) increase in SCFAs (propionic, butyric and valeric acids) in the ascending colonic vessel with no changes observed with CH-GL. Only CH-OPT showed a significant (p < 0.05) increase in BCFAs, also noted in the ascending colon. No significant (p < 0.05) changes to SCFAs and BCFAs were observed in the transverse and descending colons for both CHs. These findings demonstrate that CHs can induce microbial production of SCFAs and BCFAs although this appears to depend on the CH tested. More studies are needed to determine the physiological significance of these microbial metabolites from intake of CH supplements.

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Vieira, Antonio Diogo Silva, Carlota Bussolo de Souza, Marina Padilha, Erwin Gerard Zoetendal, Hauke Smidt, Susana Marta Isay Saad et Koen Venema. « Impact of a fermented soy beverage supplemented with acerola by-product on the gut microbiota from lean and obese subjects using an in vitro model of the human colon ». Applied Microbiology and Biotechnology 105, n^o 9 (mai 2021) : 3771–85. http://dx.doi.org/10.1007/s00253-021-11252-8.

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Abstract The aim of this study was to evaluate the effects of soy-based beverages manufactured with water-soluble soy extract, containing probiotic strains (Lactobacillus acidophilus LA-5 and Bifidobacterium longum BB-46) and/or acerola by-product (ABP) on pooled faecal microbiota obtained from lean and obese donors. Four fermented soy beverages (FSs) (“placebo” (FS-Pla), probiotic (FS-Pro), prebiotic (FS-Pre), and synbiotic (FS-Syn)) were subjected to in vitro digestion, followed by inoculation in the TIM-2 system, a dynamic in vitro model that mimics the conditions of the human colon. Short- and branched-chain fatty acids (SCFA and BCFA) and microbiota composition were determined. Upon colonic fermentation in the presence of the different FSs formulations, acetic and lactic acid production was higher than the control treatment for faecal microbiota from lean individuals (FMLI). Additionally, SCFA production by the FMLI was higher than for the faecal microbiota from obese individuals (FMOI). Bifidobacterium spp. and Lactobacillus spp. populations increased during simulated colonic fermentation in the presence of FS-Syn in the FMLI and FMOI. FS formulations also changed the composition of the FMOI, resulting in a profile more similar to the FMLI. The changes in the composition and the increase in SCFA production observed for the FMLI and FMOI during these in vitro fermentations suggest a potential modulation effect of these microbiotas by the consumption of functional FSs. Graphical abstract Key points • Soy beverages increased Bifidobacterium abundance in microbiota from obese individuals. • The synbiotic beverage increased Bifidobacterium abundance in microbiota from lean individuals. • The synbiotic beverage changed the microbiota from obese individuals, approaching the lean profiles.

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Larder, Christina E., Michèle M. Iskandar et Stan Kubow. « Gastrointestinal Digestion Model Assessment of Peptide Diversity and Microbial Fermentation Products of Collagen Hydrolysates ». Nutrients 13, n^o 8 (7 août 2021) : 2720. http://dx.doi.org/10.3390/nu13082720.

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Osteoarthritis (OA), the most common form of arthritis, is associated with metabolic diseases and gut microbiome dysbiosis. OA patients often take supplements of collagen hydrolysates (CHs) with a high peptide content. Following digestion, some peptides escape absorption to induce prebiotic effects via their colonic fermentation to generate short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs) and colonic gases (NH4 and H2S). The capacity of CHs to generate microbial metabolites is unknown. Proteomic analysis of two CHs (CH-GL and CH-OPT) demonstrated different native peptide profiles with increased peptide diversity after in vitro gastric and small intestinal digestion. Subsequent 24 h fermentation of the CH digests in a dynamic gastrointestinal (GI) digestion model containing human fecal matter showed that CH-OPT increased (p < 0.05) H2S, SCFAs (propionic, butyric and valeric acids), BCFAs, and decreased NH4 in the ascending colon reactor with no major changes seen with CH-GL. No major effects were observed in the transverse and descending vessels for either CH. These findings signify that CHs can induce prebiotic effects in the ascending colon that are CH dependent. More studies are needed to determine the physiological significance of CH-derived colonic metabolites, in view of emerging evidence connecting the gut to OA and metabolic diseases.

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Kiefer, Jeannette, Gabriele Beyer-Sehlmeyer et Beatrice L. Pool-Zobel. « Mixtures of SCFA, composed according to physiologically available concentrations in the gut lumen, modulate histone acetylation in human HT29 colon cancer cells ». British Journal of Nutrition 96, n^o 5 (novembre 2006) : 803–10. http://dx.doi.org/10.1017/bjn20061948.

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Intake of fibre has beneficial properties on gut health. Butyrate, a product of bacterial gut fermentation, is thought to contribute to positive effects by retarding growth and enhancing apoptosis of tumour cells. One mechanism is seen in its capacity to modulate histone acetylation and thereby transcriptional activity of genes. Next to butyrate, propionate and acetate are also major products of gut fermentation and together they may exert different potencies of cellular effects than butyrate alone. Since virtually nothing is known on combination effects by SCFA mixtures, here we had the aim to assess how physiological relevant concentrations and mixtures of SCFA modulate histone acetylation in human colon cells. HT29 colon cancer cells were incubated with mixtures of butyrate, acetate and propionate and with the individual compounds as controls. Histone acetylation was determined with acid-urea gel electrophoresis and immunoblotting. Acetylated histones slowly increased over 24 h and persisted up to 72 h in butyrate-treated HT29 cells. Butyrate (5–40 mm) and propionate (20–40 mm) enhanced histone acetylation significantly after 24 h incubation, whereas acetate (2·5–80 mm) was ineffective. Mixtures of these SCFA also modulated histone acetylation, mainly due to additive effects of butyrate and propionate, but not due to acetate. In conclusion, physiological concentrations of propionate together with butyrate could have more profound biological activities than generally assumed. Together, these SCFA could possibly mediate important processes related to an altered transcriptional gene activation and thus contribute to biological effects possibly related to cancer progression or prevention.

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Vesely, Ondrej, Petr Marsik, Veronika Jarosova, Ivo Doskocil, Karel Smejkal, Pavel Kloucek et Jaroslav Havlik. « Metabolism of Selected 2-Arylbenzofurans in a Colon In Vitro Model System ». Foods 10, n^o 11 (10 novembre 2021) : 2754. http://dx.doi.org/10.3390/foods10112754.

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2-arylbenzofurans represent a small group of bioactive compounds found in the plant family Moraceae. As it has not been investigated whether these substances are stable during passage through the gastrointestinal tract, their biological effects may be altered by the metabolism of intestinal microbiota or cells. The aim of the present study was to investigate and compare mulberrofuran Y (1), moracin C (2), and mulberrofuran G (3) in an in vitro model of human intestinal bacterial fermentation and in an epithelial model using the Caco-2 cell line. The analysis of compounds by LC-MS-Q-TOF showed sufficient stability in the fermentation model, with no bacterial metabolites detected. However, great differences in the quantity of permeation were observed in the permeability assay. Moreover, mulberrofuran Y (1) and moracin C (2) were observed to be transformed into polar metabolites by conjugation. Among the test compounds, mulberrofuran Y (1) was mostly stable and accumulated in endothelial cells (85.3%) compared with mulberrofuran G (3) and moracin C (2) (14% and 8.2%, respectively). Thus, only a small amount of mulberrofuran Y (1) was conjugated. Moracin C (2) and mulberrofuran G (3) were metabolized almost completely, with only traces of the unchanged molecule being found on the apical and cellular sides of the system. Only conjugates of mulberrofuran Y (1) and moracin C (2) were able to reach the basolateral side. Our results provide the basic description of bioavailability of these three compounds, which is a necessary characteristic for final evaluation of bio-efficacy.

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Gietl, Eva, Wim Mengerink, Jaap de Slegte, Glenn Gibson, Robert Rastall et Ellen van den Heuvel. « Factors Involved in the In Vitro Fermentability of Short Carbohydrates in Static Faecal Batch Cultures ». International Journal of Carbohydrate Chemistry 2012 (18 décembre 2012) : 1–10. http://dx.doi.org/10.1155/2012/197809.

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In recent years, research has focused on the positive effects of prebiotics on intestinal health and gut microbiota. The relationship between their chemical structure and their fermentation pattern by human intestinal microbiota is still not well understood. The aim of this study was to improve understanding of this relationship and identify factors that may be used to design galactooligosaccharides that reach more distal regions than commercial prebiotics which mainly target the proximal colon. The following factors were investigated: monomer type, linkage, substitution, and degree of polymerisation. Total organic acid production from sugars by faecal bacteria was fitted to a model which allowed an estimate of the time when half of the maximal organic acid concentration was reached (T50) in static faecal batch cultures. The different factors can be grouped by their effectiveness at prolonging fermentation time as follows: substitution is most effective, with methylgalactose, β-galactose-pentaacetate, D-fucose, and galactitol fermented more slowly than D-galactose. Monomers and linkage also influence fermentation time, with L rhamnose, arabinose, melezitose, and xylose being fermented significantly slower than D-glucose (P<0.05), maltose, isomaltose, cellobiose, and gentiobiose showing that Glcα1-6Glc and Glcβ1-4Glc were utilised slowest. Chain length had the smallest effect on fermentation time.

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Lim, Su-Jin, Hyuk-Cheol Kwon, Dong-Min Shin, Yong-Jun Choi, Seo-Gu Han, Yea-Ji Kim et Sung-Gu Han. « Apoptosis-Inducing Effects of Short-Chain Fatty Acids-Rich Fermented Pistachio Milk in Human Colon Carcinoma Cells ». Foods 12, n^o 1 (1 janvier 2023) : 189. http://dx.doi.org/10.3390/foods12010189.

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Pistachio milk (PM), an extraction product of pistachio, is protein- and fat-dense food. Short-chain fatty acids (SCFAs) are known for inducing cytotoxicity and apoptosis in colon carcinoma cells. This study aimed to find an optimal combination of probiotics that can produce a higher amount of SCFAs in PM. In addition, the anti-cancer effect of fermented PM on human colon carcinoma cells (Caco-2) was determined. The combinations of probiotics were as follows: Streptococcus thermophilus + Lactobacillus bulgaricus (C); C + Lactobacillus acidophilus (C-La); C + Lactobacillus gasseri (C-Lg); C + Bifidobacterium bifidum (C-Bb). The results indicated that fermented PM was produced after a short fermentation time in all the probiotics combinations. C-Bb produced up to 1.5-fold more acetate than the other probiotics combinations did. A significant amount of cytotoxicity, i.e., 78, 56, and 29% cell viability was observed in Caco-2 cells by C-Bb-fermented PM at 1, 2.5 and 5%, respectively. C-Bb-fermented PM (5%) induced early and late apoptosis up to 6-fold. Additionally, Caco-2 cells treated with C-Bb-fermented PM significantly induced the downregulation of α-tubulin and the upregulation of cleaved caspase-3, as well as nuclear condensation and fragmentation. Our data suggest that fermented PM, which is rich in acetate, may have the potential as a functional food possessing anti-colon cancer properties.

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Shewry, Peter R., Brittany Hazard, Alison Lovegrove et Cristobal Uauy. « Improving starch and fibre in wheat grain for human health ». Biochemist 42, n^o 4 (31 juillet 2020) : 40–45. http://dx.doi.org/10.1042/bio20200051.

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Reducing the prevalence of diet-related diseases, including obesity and type 2 diabetes, is a major challenge for health professionals, food manufacturers and governments in both developed and developing countries. Cereals are key targets in meeting this challenge as they are staple foods throughout the world and major sources of energy (derived principally from starch) and dietary fibre. Wheat is the staple cereal in the UK and Europe, and the UK Biotechnology and Biological Sciences Research Council (BBSRC)-supported Designing Future Wheat programme is focused on manipulating the content and composition of starch and fibre to improve health impacts, including reducing the glycaemic response and improving fermentation in the colon. This work is contributing to the development of improved cultivars by breeders and foods by processors. It is also increasing our understanding of the behaviour of these components in the human gastrointestinal (GI) tract and will contribute to the establishment of targets and recommendations for regulatory authorities.

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Articles de revues sur le sujet « Human colon fermentation »

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