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Relevant bibliographies by topics / Human colon fermentation

Academic literature on the topic 'Human colon fermentation'

Author: Grafiati

Published: 11 March 2023

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Journal articles on the topic "Human colon fermentation"

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Arrigoni, Eva, Fred Brouns, and Renato Amadò. "Human gut microbiota does not ferment erythritol." British Journal of Nutrition 94, no. 5 (November 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, no. 5 (October 1995): 353–58. http://dx.doi.org/10.1097/00008469-199510000-00004.

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Probert, H. M., and G. R. Gibson. "Development of a fermentation system to model sessile bacterial populations in the human colon." Biofilms 1, no. 1 (January 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, and B. Flourié. "Fermentation of starch stimulates propagated contractions in the human colon." Neurogastroenterology & Motility 23, no. 5 (December 28, 2010): 450—e176. http://dx.doi.org/10.1111/j.1365-2982.2010.01652.x.

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Cummings, J. H., and G. T. Macfarlane. "The control and consequences of bacterial fermentation in the human colon." Journal of Applied Bacteriology 70, no. 6 (June 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, and J. H. Cummings. "Comparison of fermentation reactions in different regions of the human colon." Journal of Applied Bacteriology 72, no. 1 (January 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, and J. H. Cummings. "Comparison of fermentation reactions in different regions of the human colon." Journal of Applied Microbiology 72, no. 1 (January 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, and A. R. Walker. "Alternative pathways for hydrogen disposal during fermentation in the human colon." Gut 31, no. 6 (June 1, 1990): 679–83. http://dx.doi.org/10.1136/gut.31.6.679.

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9

Cummings, J. H., and H. N. Englyst. "Measurement of starch fermentation in the human large intestine." Canadian Journal of Physiology and Pharmacology 69, no. 1 (January 1, 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, and 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, no. 3 (2020): 2626–38. http://dx.doi.org/10.1039/c9fo03009c.

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Dissertations / Theses on the topic "Human colon fermentation"

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Trinidad, Trinidad Palad. "Calcium absorption in the human distal colon, effect of short chain fatty acids from fiber fermentation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ28071.pdf.

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Probert, Hollie Marie. "An investigation of the lumenal and mucosal microflora of the human colon : effects of prebiotics on bacteriology and gas generation." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252247.

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Barcenilla, Adela. "Diversity of the butyrate-producing microflora of the human gut." Thesis, Robert Gordon University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310425.

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Robertson, Margaret Denise. "Kinetics of starch digestion and glucose assimilation in normal and colectomized humans." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362476.

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Lebet, Vincent Lebet Thierry Vincent Lebet Thierry Vincent Lebet Thierry Vincent. "Fermentations dans le côlon humain : développement et caractérisation d'une méthode in vitro /." [S.l.] : [s.n.], 1996. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11597.

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Léal, Françoise. "Etude de la production et de l'émanation de composés volatils malodorants sur textile à usage sportif." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL070N/document.

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Si la sueur fraîchement émise par le corps humain est inodore, la dégradation de celle-ci par la flore bactérienne cutanée produit des composés volatils malodorants, responsables des odeurs de transpiration. Les odeurs de transpiration apparaissent également sur les vêtements au cours de leur utilisation, particulièrement sur les textiles réalisés en fibres synthétiques. Ce travail a pour but d’améliorer la compréhension du phénomène d’émanation d’odeurs en étudiant l’effet du sujet testé, l’effet de la flore bactérienne et l’effet du textile sur les émissions de composés volatils malodorants.L’intérêt de ce travail réside dans l’approche globale de la problématique des odeurs de transpiration et dans la diversité des méthodes de mesure mises en place, tant dans l’étude de la flore microbiologique que dans les méthodes de mesures des composés odorants émis.Dans un premier temps, le dénombrement simultané de la flore bactérienne sur la peau et sur le vêtement a été réalisé sur un échantillon de 15 sujets à l’issue d’un exercice physique. Cette expérimentation a permis d’évaluer le taux de transfert bactérien moyen lors d’une activité sportive et d’étudier son rôle dans l’émission d’odeurs. Ensuite, afin d’affiner ces résultats, une méthode basée sur la biologie moléculaire a été mise en place pour réaliser le suivi qualitatif de la stabilité de la flore commensale axillaire d’un sujet pendant 3 mois. Le transfert bactérien spécifique entre la peau du testeur et le vêtement a été étudié pour 4 matières textiles sélectionnées (dont le coton et le PET). Ceci a permis de déterminer le rôle du transfert bactérien spécifique dans l’émission des odeurs à partir de textile.Enfin, le dernier chapitre est consacré à l’étude de l’émission de composés volatils et odorants à l’aide de mesures olfactives et d’un nez électronique au cours du temps par 8 composants textiles sélectionnés. Après traitement statistique par analyse en composante principale et étude détaillée des mesures, 9 composés chimiques ont été identifiés comme indicateurs d’un comportement textile malodorant. Ces derniers pourraient être utilisés dans la mise en place d’une méthode ciblée de mesure physico-chimique des mauvaises odeurs.Ce travail a permis de déterminer l’impact de chacun des facteurs sujet, flore bactérienne et textile dans l’émission d’odeurs. En outre, ce travail ouvre des perspectives sur l’étude des contaminations bactériennes par contact, mais également dans l’étude des odeurs, sur les phénomènes de désorption de molécules volatiles à partir de différentes matrices textiles et sur les solutions pouvant être envisagées pour limiter les émissions odorantes à partir de textiles
Fresh human sweat is odorless. Odoriferous volatile compounds are produced by the metabolism of bacteria living on the skin, generating strong malodor. Sweaty body odors do also appear on clothes during use, and especially on synthetic fabrics. The aim of this document is to improve understanding of odor emission by investigating subject effect, microbiota effect and fabric effect on the emission of odoriferous volatile compounds.Odors of perspiration are hereby globally approached with a wide use of methods and experimental devices, for microbial flora study as well as for odoriferous volatile compounds emission study.First, microflora enumeration has been simultaneously processed on the skin and on the fabric after exercise for 15 subjects. This experiment allowed an evaluation of the average bacterial transfer yield during physical activity and the beginning of the investigation of its effect on odor emission.A molecular biology methodology has then been developed in order to refine these results. Monitoring of qualitative composition of the microbiota has been performed to study the stability of the armpit’s ecosystem on a subject during 3 months. Specific microbial transfer from subject’s skin to clothe has been performed for 4 textile fabrics (including cotton and PET). This leaded to characterize the effect of specific bacterial transfer on odor emission from fabric.The last chapter is dedicated to the study of the emission of odoriferous volatile compounds over time using olfactory measurements and electronic nose for 8 selected fabrics. Principal component analysis targeted 9 chemical compounds that have been selected as malodorous behavior indicators for a given fabric. Those 9 compounds could be used for setting up a fitted physicochemical method of malodor.To conclude, this study helped to understand the effect of 3 factors in odor perception from a fabric after sport : subject, microbial flora and fabric. Perspectives have been charted on contact microbial contamination, but also on odor, and especially on desorption of odoriferous volatile molecules from a textile or knitted matrix. The solutions that could be used to limit malodorous emission from fabrics have also been discussed

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(5930684), Rachel M. Jackson. "Consequences of Dietary Fibers and their Proportion on the Fermentation of Dietary Protein by Human Gut Microbiota." Thesis, 2019.

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In the human gut, bacterial fermentation of dietary fibers and proteins produces metabolites, primarily as short-chain fatty acids (SCFA), that are highly beneficial for host health. However, unlike dietary fiber, bacterial fermentation of protein additionally generates potentially toxic substances such as ammonia, hydrogen sulfide, amines, and indoles. It is believed that most gut bacteria favor utilization of dietary fiber over that of protein for energy. Therefore, when fermentable dietary fiber is readily available to colonic bacteria, protein fermentation, and its subsequent potentially toxic metabolites, remains relatively low. Dietary intake primarily determines the quantity of dietary fiber and protein substrate available to the gut microbiota and the resulting profile of metabolites produced. Increased protein consumption is associated with deleterious health outcomes such as higher risk of colorectal cancer and type II diabetes. Conversely, diets following US dietary recommendations are high in fiber, which promote a healthy microbiome and are protective against disease. Diets following the recommendation are also moderate in protein intake so that, ultimately, far more fiber than protein is available for colonic bacterial fermentation. On the contrary, dietary fiber intake is chronically low in a standard Western diet, while protein consumption is above dietary recommendations, which results in nearly equal amounts of dietary fiber and protein available for gut microbial fermentation. Furthermore, the popularity of high-protein diets for athletes, as well as that of high-protein low-carbohydrate diets for weight loss, may flip fiber and protein substrate proportions upside down, resulting in more protein than fiber available in the gut for fermentation. The objective of this study was to elucidate how substrate ratios in protein-fiber mixtures affect protein fermentation and metabolites, as well as examine the degree to which fiber source may influence these outcomes. Each dietary fiber source [fructooligosaccharides (FOS), apple pectin (Pectin), a wheat bran and raw potato starch mixture (WB+PS), and an even mixture of the three aforementioned fibers (Even Mix)] and protein were combined in three ratios and provided as substrate for in vitro fecal fermentation to understand how low, medium, and high fiber inclusion levels influence fermentation outcomes. They were compared to 100% protein and fiber (each different fiber) controls. Branched-chain fatty acids (BCFAs), metabolites produced exclusively from protein fermentation, were used as a measure of protein fermentation; the data were normalized based on the initial quantity of protein within the substrate. In protein-fiber substrate mixtures, only FOS and Even Mix inhibited BCFAs (mM/g protein basis) and only when they made up at least half of the substrate. Unexpectedly, the rate of protein fermentation was increased when the protein-fiber substrate contained 25% WB+PS fiber, possibly due to the starch component of the fiber. There was evidence that when pH drops during fermentation, as was the case for protein-FOS mixtures, it played a significant role in suppressing protein fermentation. Ammonia production was not largely affected by increasing the proportion of dietary fiber. A significant reduction did not occur until FOS made up at least 50% of the protein-fiber substrate; for Pectin, WB+PS, and Even Mix fibers, 75% inclusion was required for a significant decrease in ammonia. Interestingly, protein was butyrogenic. Protein as the sole substrate produced more butyrate than either Pectin or Even Mix as the sole substrates, and in fact, addition of Pectin to protein significantly reduced butyrate concentrations. However, the possible benefits of butyrate produced via protein fermentation needs to be tempered by the production of potentially toxic compounds and the association between protein fermentation and colorectal cancer. Overall, the thesis findings showed protein fermentation to be relatively stable and not easily influenced by increasing the availability of dietary fiber, and no clear evidence of microbial preference for carbohydrates over protein was found.

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Ceppa, Florencia Andrea. "Diet:microbiota interaction in the gut focus on amino acid metabolism." Doctoral thesis, 2016. http://hdl.handle.net/10449/33118.

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This study aims to measure the impact of protein and amino acid fermentation on the composition and metabolic output of gut microbiota. Although dissimilatory pathways have been described for most amino acids, microbial degradation routes within the gut microbiota are relatively unexplored. The objectives were (1) to characterize amino acid breakdown by the colonic microbiota, (2) to determine the fermentation products formed from individual amino acids/protein (3) to examine how amino acid metabolism is impacted by the presence of a fermentable fiber (prebiotic inulin) and finally (4) to evaluate with an in vivo model (trout fish) diet:- microbe interactions and the development of gut microbiota during fish farming. Interactions between the healthy human intestinal microbiota of the distal colon and different combinations of nutrients were simulated using in vitro pH-controlled anaerobic batch cultures of human faeces. Combining high-throughput sequencing of 16S rRNA amplicons, with high-throughput 1 H NMR, changes in faecal microbiota composition and metabolic output were measured. During exogenous substrate microbial fermentation (e.g. beef, Trp or fish feed) in the large bowel bioactive compounds (harmful or beneficial) are produced. Many factors affect the gut-microbial metabolism including pH, type and quantity of growth substrate (e.g. protein/carbohydrate) and make up of the gut microbiota. Considerable interindividual variation was observed in response to different digested substrates but over all, the beneficial impact of prebiotic fiber fermentation on production of bioactive compounds from amino acids/proteins was confirmed in this study. In trout, although our dietary intervention with essential oils had little impact on the gut microbiota, the study showed for the first time a dramatic shift in the composition and diversity of the gut microbiota in juvenile compared to adult fish. These observations may have relevance in designing dietary strategies to reduce chronic diseases like colon cancer and heart disease and for fish farming respectively

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Books on the topic "Human colon fermentation"

1

Trinidad, Trinidad Palad. Calcium absorption in the human distal colon: Effect of short chain fatty acids from fiber fermentation. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1997.

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Book chapters on the topic "Human colon fermentation"

1

De Vuyst, L., and F. Leroy. "Chapter 18 Cross-feeding during human colon fermentation." In The value of fibre, 313–38. The Netherlands: Wageningen Academic Publishers, 2019. http://dx.doi.org/10.3920/978-90-8686-893-3_18.

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Ismail, Mona M. "Probiotics and Algal Functional Food." In Algal Functional Foods and Nutraceuticals: Benefits, Opportunities, and Challenges, 341–61. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815051872122010018.

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The aim of this work is to explain the probiotic activity of algae and the role of their bioactive compounds as a dietary supplement for promoting growth and disease resistance. Micro- and macroalgae are good alternatives to chemical probiotics because they contain important and safe functional components such as polysaccharides, fatty acids, pigment and proteins, which are considered an extraordinary source of prebiotics with health benefits and enhance healthy colonic microbiota composition. Recently, algae and their extracts have been employed in ingestion systems, simulating the human colon, or animal models. Especially, macroalgae and their polysaccharides have been used for decades to improve human health depending on saccharolytic fermentation by the gut microbiota. Generally, the addition of algae leads to enhance the viability of probiotic bacteria, the acidity of food, and storage quality and, consequently, prevent certain human diseases. Therefore, further investigations should be done for screening and identifying putative prebiotic compounds from algae via the host organism's identification, which utilizes algal bioactive metabolites produced. There will be a need for increasing algae production to replace or supplement the intake of plant foods of terrestrial origin.

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Taber, Douglass. "Alkaloid Synthesis: Crispine A (Zhou), Cermizine C (Zhang), Tangutorine (Poupon), FR901483 (Kerr), Serratezomine A (Johnston)." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0061.

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Enantioselective hydrogenation of enamides is a well-established transformation. The corresponding reduction of enamines has been elusive. Qi-Lin Zhou of Nankai University designed (J. Am. Chem. Soc. 2009, 131, 1366) an Ir catalyst that reduced 2 to the Carpus alkaloid Crispine A 3 in high ee. Direct conversion of C-H to C-C bonds is a powerful synthetic transformation. Liming Zhang, now at the University of California, Santa Barbara, observed (J. Am. Chem. Soc. 2009, 131, 8394) that a gold catalyst converted the N-oxide of 4 into 5, that was then deoxygenated to give Cermizine C 6. The gold catalyst and the N-oxide combined to convert the alkyne into an α-keto carbene, in the process reducing the N-oxide back to the amine. The carbene then abstracted a hydride from the carbon adjacent to the amine, generating an intermediate that collapsed to give 5 with high diastereocontrol. Tangutorine 10, isolated from the leaves of Nitraria tangutorum, affects the morphology of human colon cancer cells. In a biomimetic approach, Erwan Poupon of the Université Paris-Sud stirred (Organic Lett . 2009, 11, 1891) glutaraldehyde 7 with bicarbonate to give an unstable carbocyclic dimer. Addition of tryptamine in acetic acid delivered the pentacyclic product 9, that was reduced with borohydride to give the crystalline Tangutorine 10. FR901483, a potent immunosuppressive isolated from a Cladobotyrum fermentation broth, presents an challenging array of stereogenic centers in its tricyclic skeleton. Michael A. Kerr of the University of Western Ontario prepared (Organic Lett. 2009, 11, 777) the activated cyclopropane 11, then effected intramolecular dipolar opening with an intermediate imine, yielding the tricyclic 12. The Lycopodium alkaloid Serratezomine A 21 presents a similarly challenging array of stereogenic centers in its tetracyclic structure. Jeffrey N. Johnston of Vanderbilt University constructed (J. Am. Chem. Soc. 2009, 131, 3470) the pyrrolidine ring of 15 using the imine free radical acceptor that he had previously developed. Having the alkene-Sn bond in place then enabled coupling with the acid chloride 16. Oxidative deprotection of 17 freed the enamine, that added in a conjugate sense to the unsaturated ester, kinetically setting the axial branch of 18.

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Cox, Timothy M. "Disaccharidase deficiency." In Oxford Textbook of Medicine, edited by Jack Satsangi, 2902–9. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0302.

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Disaccharidases are abundant enzymes expressed on the microvillous membrane of the small intestine: apart from free glucose and fructose, disaccharidases are required for the complete assimilation of nearly all carbohydrate present in food and drinks. The enzymes cleave disaccharides such as sucrose, maltose, and lactose, as well as dextrins derived from starch, into their component monosaccharides. Their activity is reduced in hereditary conditions or in generalized intestinal diseases. Disaccharidase deficiency causes dietary intolerance of carbohydrate induced by the fermentation of undigested sugars in the distal small intestine and colon. Abdominal symptoms are usually noticed within an hour of the ingestion of foods containing the offending sugars. By far the most common symptomatic disaccharidase deficiency is lactose intolerance. Lactase activity is high in healthy infants when milk is the principal food, but in most humans the activity declines after weaning and remains low (lactase nonpersistence), which greatly reduces the capacity to break down lactose. In contrast, those inheriting a Mendelian dominant trait that leads to sustained high intestinal lactase expression throughout life (lactase persistence) digest and tolerate large quantities. The distribution of lactase activity in adult populations is subject to great variation. Intestinal lactase phenotypes can be identified by assay of mucosal biopsy samples or appropriate sugar tolerance tests, as can other (much rarer) genetically determined disaccharidase variants. The most convenient diagnostic screen involves hydrogen breath testing after oral loading. Disaccharide intolerance is readily treated by institution of a strict exclusion diet; oral enzymatic supplementation may benefit patients with severe enzymatic deficiency. Innovative and early phase clinical trials suggest that modulation of the host intestinal microbiome with a pure short-chain galacto-oligosaccharide may be beneficial in symptom control and in favouring the outgrowth of lactose-fermenting flora.

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