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Christophe Lacroix - One of the best experts on this subject based on the ideXlab platform.

  • Stepwise Development of an in vitro Continuous Fermentation Model for the Murine Caecal Microbiota.
    Frontiers in Microbiology, 2019
    Co-Authors: Sophie A. Poeker, Christophe Lacroix, Tomas De Wouters, Marianne R. Spalinger, Michael Scharl, Annelies Geirnaert
    Abstract:

    Murine Models are valuable tools to study the role of gut microbiota in health or disease. However, murine and human microbiota differ in species composition, so further investigation of the murine gut microbiota is important to gain a better mechanistic understanding. Continuous in vitro Fermentation Models are powerful tools to investigate microbe-microbe interactions while circumventing animal testing and host confounding factors, but are lacking for murine gut microbiota. We therefore developed a novel continuous Fermentation Model based on the PolyFermS platform adapted to the murine caecum and inoculated with immobilized caecal microbiota. We followed a stepwise Model development approach by adjusting parameters [pH, retention time (RT), growth medium] to reach Fermentation metabolite profiles and marker bacterial levels similar to the inoculum. The final Model had a stable and inoculum-alike Fermentation profile during continuous operation. A lower pH during startup and continuous operation stimulated bacterial Fermentation (115 mM short-chain fatty acids at pH 7 to 159 mM at pH 6.5). Adjustments to nutritive medium, a decreased pH and increased RT helped control the in vitro Enterobacteriaceae levels, which often bloom in Fermentation Models, to 6.6 log gene copies/mL in final Model. In parallel, the Lactobacillus, Lachnospiraceae, and Ruminococcaceae levels were better maintained in vitro with concentrations of 8.5 log gene copies/mL, 8.8 log gene copies/mL and 7.5 log gene copies/mL, respectively, in the final Model. An independent repetition with final Model parameters showed reproducible results in maintaining the inoculum Fermentation metabolite profile and its marker bacterial levels. Microbiota community analysis of the final Model showed a decreased bacterial diversity and compositional differences compared to caecal inoculum microbiota. Most of the caecal bacterial families were represented in vitro, but taxa of the Muribaculaceae family were not maintained. Functional metagenomics prediction showed conserved metabolic and functional KEGG pathways between in vitro and caecal inoculum microbiota. To conclude, we showed that a rational and stepwise approach allowed us to Model in vitro the murine caecal microbiota and functions. Our Model is a first step to develop murine microbiota Model systems and offers the potential to study microbiota functionality and structure ex vivo.

  • understanding the prebiotic potential of different dietary fibers using an in vitro continuous adult Fermentation Model polyferms
    Scientific Reports, 2018
    Co-Authors: Sophie A. Poeker, Tomas De Wouters, Annelies Geirnaert, Laura Berchtold, Anna Greppi, Lukasz Krych, Robert E Steinert, Christophe Lacroix
    Abstract:

    Consumption of fermentable dietary fibers (DFs), which can induce growth and/or activity of specific beneficial populations, is suggested a promising strategy to modulate the gut microbiota and restore health in microbiota-linked diseases. Until today, inulin and fructo-oligosaccharides (FOS) are the best studied DFs, while little is known about the gut microbiota-modulating effects of β-glucan, α-galactooligosaccharide (α-GOS) and xylo-oligosaccharide (XOS). Here, we used three continuous in vitro Fermentation PolyFermS Model to study the modulating effect of these DFs on two distinct human adult proximal colon microbiota, independently from the host. Supplementation of DFs, equivalent to a 9 g daily intake, induced a consistent metabolic response depending on the donor microbiota. Irrespective to the DF supplemented, the Bacteroidaceae-Ruminococcaceae dominated microbiota produced more butyrate (up to 96%), while the Prevotellaceae-Ruminococcaceae dominated microbiota produced more propionate (up to 40%). Changes in abundance of specific bacterial taxa upon DF supplementation explained the observed changes in short-chain fatty acid profiles. Our data suggest that the metabolic profile of SCFA profile may be the most suitable and robust read-out to characterize microbiota-modulating effects of a DF and highlights importance to understand the inter-individual response to a prebiotic treatment for mechanistic understanding and human application.

  • Synergistic effects of Bifidobacterium thermophilum RBL67 and selected prebiotics on inhibition of Salmonella colonization in the swine proximal colon PolyFermS Model
    Gut Pathogens, 2014
    Co-Authors: Sabine A Tanner, Annina Zihler Berner, Christophe Chassard, Christophe Lacroix
    Abstract:

    Background Probiotics and prebiotics are promising strategies to counteract Salmonella prevalence in swine. In the present study, we investigated the effects of prebiotics (fructo- (FOS), galacto- (GOS) and mannan- (MOS) oligosaccharides) and the bacteriocinogenic Bifidobacterium thermophilum RBL67 (RBL67) on Salmonella enterica subsp. enterica serovar Typhimurium N-15 (N-15) colonization using the PolyFermS in vitro continuous Fermentation Model simulating the swine proximal colon.

  • in vitro continuous Fermentation Model polyferms of the swine proximal colon for simultaneous testing on the same gut microbiota
    PLOS ONE, 2014
    Co-Authors: Sabine A Tanner, Annina Zihler Berner, Eugenia Rigozzi, Franck Grattepanche, Christophe Chassard, Christophe Lacroix
    Abstract:

    In vitro gut Modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal Fermentation Models are mainly batch Models with important inherent limitations. In this study we developed a novel in vitro continuous Fermentation Model, mimicking the porcine proximal colon, which we validated during 54 days of Fermentation. This Model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v) five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The Model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic Fermentation.

  • monitoring horizontal antibiotic resistance gene transfer in a colonic Fermentation Model
    FEMS Microbiology Ecology, 2011
    Co-Authors: Martina C Haug, Sabine A Tanner, Christophe Lacroix, Marc J A Stevens, Leo Meile
    Abstract:

    The human microbiota is suggested to be a reservoir of antibiotic resistance (ABR) genes, which are exchangeable between transient colonizers and residing bacteria. In this study, the transfer of ABR genes from Enterococcus faecalis to Listeria monocytogenes and to commensal bacteria of the human gut microbiota was demonstrated in a colonic Fermentation Model. In the first Fermentation, an E. faecalis donor harboring the marked 50-kb conjugative plasmid pRE25* and a chromosomal marker was co-immobilized with L. monocytogenes and infant feces. In this complex environment, the transfer of pRE25* to L. monocytogenes was observed. In a second Fermentation, only the E. faecalis donor and feces were co-immobilized. Enumeration of pRE25* and the donor strain by quantitative PCR revealed an increasing ratio of pRE25* to the donor throughout the 16-day Fermentation, indicating the transfer of pRE25*. An Enterococcus avium transconjugant was isolated, demonstrating that ABR gene transfer to gut commensals occurred. Moreover, pRE25* was still functional in both the E. avium and the L. monocytogenes transconjugant and transmittable to other genera in filter mating experiments. Our study reveals that the transfer of a multiresistance plasmid to commensal bacteria in the presence of competing fecal microbiota occurs in a colonic Model, suggesting that commensal bacteria contribute to the increasing prevalence of antibiotic-resistant bacteria.

Angelo Fontana - One of the best experts on this subject based on the ideXlab platform.

  • Model development and experimental validation of capnophilic lactic Fermentation and hydrogen synthesis by thermotoga neapolitana
    Water Research, 2016
    Co-Authors: Laura Dipasquale, Angelo Fontana, Giuliana Dippolito, Nirakar Pradhan, Antonio Panico, Francesco Pirozzi, Piet N L Lens, Giovanni Esposito
    Abstract:

    Abstract The aim of the present study was to develop a kinetic Model for a recently proposed unique and novel metabolic process called capnophilic (CO 2 -requiring) lactic Fermentation (CLF) pathway in Thermotoga neapolitana . The Model was based on Monod kinetics and the mathematical expressions were developed to enable the simulation of biomass growth, substrate consumption and product formation. The calibrated kinetic parameters such as maximum specific uptake rate ( k ), semi-saturation constant ( k S ), biomass yield coefficient ( Y ) and endogenous decay rate ( k d ) were 1.30 h −1 , 1.42 g/L, 0.1195 and 0.0205 h −1 , respectively. A high correlation (>0.98) was obtained between the experimental data and Model predictions for both Model validation and cross validation processes. An increase of the lactate production in the range of 40–80% was obtained through CLF pathway compared to the classic dark Fermentation Model. The proposed kinetic Model is the first mechanistically based Model for the CLF pathway. This Model provides useful information to improve the knowledge about how acetate and CO 2 are recycled back by Thermotoga neapolitana to produce lactate without compromising the overall hydrogen yield.

  • capnophilic lactic Fermentation and hydrogen synthesis by thermotoga neapolitana an unexpected deviation from the dark Fermentation Model
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Laura Dipasquale, Giuliana Dippolito, Angelo Fontana
    Abstract:

    Abstract The heterotrophic bacterium Thermotoga neapolitana produces hydrogen by Fermentation of organic substrates. The process is referred to as dark Fermentation and is typically complemented by production of acetic acid. Here we show that synthesis of products derived by reductive metabolism of pyruvate, mainly lactic acid, occurs to the detriment of acetic acid Fermentation when the cultures of the thermophilic bacterium are flushed by saturating level of CO 2 . Sodium bicarbonate in a very narrow range of concentrations (∼14 mM) also causes the same metabolic shift. The capnophilic (CO 2 -requiring) re-orientation of the fermentative process toward lactic acid does not affect hydrogen productivity thus challenging the currently accepted dark Fermentation Model that predicts reduction of this gas when glucose is converted into organic products different from acetate.

  • Capnophilic lactic Fermentation and hydrogen synthesis by Thermotoga neapolitana: An unexpected deviation from the dark Fermentation Model
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Laura Dipasquale, Giuliana D'ippolito, Angelo Fontana
    Abstract:

    The heterotrophic bacterium Thermotoga neapolitana produces hydrogen by Fermentation of organic substrates. The process is referred to as dark Fermentation and is typically complemented by production of acetic acid. Here we show that synthesis of products derived by reductive metabolism of pyruvate, mainly lactic acid, occurs to the detriment of acetic acid Fermentation when the cultures of the thermophilic bacterium are flushed by saturating level of CO2. Sodium bicarbonate in a very narrow range of concentrations (∼14 mM) also causes the same metabolic shift. The capnophilic (CO 2-requiring) re-orientation of the fermentative process toward lactic acid does not affect hydrogen productivity thus challenging the currently accepted dark Fermentation Model that predicts reduction of this gas when glucose is converted into organic products different from acetate. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 18.

Laura Dipasquale - One of the best experts on this subject based on the ideXlab platform.

  • Model development and experimental validation of capnophilic lactic Fermentation and hydrogen synthesis by thermotoga neapolitana
    Water Research, 2016
    Co-Authors: Laura Dipasquale, Angelo Fontana, Giuliana Dippolito, Nirakar Pradhan, Antonio Panico, Francesco Pirozzi, Piet N L Lens, Giovanni Esposito
    Abstract:

    Abstract The aim of the present study was to develop a kinetic Model for a recently proposed unique and novel metabolic process called capnophilic (CO 2 -requiring) lactic Fermentation (CLF) pathway in Thermotoga neapolitana . The Model was based on Monod kinetics and the mathematical expressions were developed to enable the simulation of biomass growth, substrate consumption and product formation. The calibrated kinetic parameters such as maximum specific uptake rate ( k ), semi-saturation constant ( k S ), biomass yield coefficient ( Y ) and endogenous decay rate ( k d ) were 1.30 h −1 , 1.42 g/L, 0.1195 and 0.0205 h −1 , respectively. A high correlation (>0.98) was obtained between the experimental data and Model predictions for both Model validation and cross validation processes. An increase of the lactate production in the range of 40–80% was obtained through CLF pathway compared to the classic dark Fermentation Model. The proposed kinetic Model is the first mechanistically based Model for the CLF pathway. This Model provides useful information to improve the knowledge about how acetate and CO 2 are recycled back by Thermotoga neapolitana to produce lactate without compromising the overall hydrogen yield.

  • capnophilic lactic Fermentation and hydrogen synthesis by thermotoga neapolitana an unexpected deviation from the dark Fermentation Model
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Laura Dipasquale, Giuliana Dippolito, Angelo Fontana
    Abstract:

    Abstract The heterotrophic bacterium Thermotoga neapolitana produces hydrogen by Fermentation of organic substrates. The process is referred to as dark Fermentation and is typically complemented by production of acetic acid. Here we show that synthesis of products derived by reductive metabolism of pyruvate, mainly lactic acid, occurs to the detriment of acetic acid Fermentation when the cultures of the thermophilic bacterium are flushed by saturating level of CO 2 . Sodium bicarbonate in a very narrow range of concentrations (∼14 mM) also causes the same metabolic shift. The capnophilic (CO 2 -requiring) re-orientation of the fermentative process toward lactic acid does not affect hydrogen productivity thus challenging the currently accepted dark Fermentation Model that predicts reduction of this gas when glucose is converted into organic products different from acetate.

  • Capnophilic lactic Fermentation and hydrogen synthesis by Thermotoga neapolitana: An unexpected deviation from the dark Fermentation Model
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Laura Dipasquale, Giuliana D'ippolito, Angelo Fontana
    Abstract:

    The heterotrophic bacterium Thermotoga neapolitana produces hydrogen by Fermentation of organic substrates. The process is referred to as dark Fermentation and is typically complemented by production of acetic acid. Here we show that synthesis of products derived by reductive metabolism of pyruvate, mainly lactic acid, occurs to the detriment of acetic acid Fermentation when the cultures of the thermophilic bacterium are flushed by saturating level of CO2. Sodium bicarbonate in a very narrow range of concentrations (∼14 mM) also causes the same metabolic shift. The capnophilic (CO 2-requiring) re-orientation of the fermentative process toward lactic acid does not affect hydrogen productivity thus challenging the currently accepted dark Fermentation Model that predicts reduction of this gas when glucose is converted into organic products different from acetate. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 18.

Sabine A Tanner - One of the best experts on this subject based on the ideXlab platform.

  • Synergistic effects of Bifidobacterium thermophilum RBL67 and selected prebiotics on inhibition of Salmonella colonization in the swine proximal colon PolyFermS Model
    Gut Pathogens, 2014
    Co-Authors: Sabine A Tanner, Annina Zihler Berner, Christophe Chassard, Christophe Lacroix
    Abstract:

    Background Probiotics and prebiotics are promising strategies to counteract Salmonella prevalence in swine. In the present study, we investigated the effects of prebiotics (fructo- (FOS), galacto- (GOS) and mannan- (MOS) oligosaccharides) and the bacteriocinogenic Bifidobacterium thermophilum RBL67 (RBL67) on Salmonella enterica subsp. enterica serovar Typhimurium N-15 (N-15) colonization using the PolyFermS in vitro continuous Fermentation Model simulating the swine proximal colon.

  • in vitro continuous Fermentation Model polyferms of the swine proximal colon for simultaneous testing on the same gut microbiota
    PLOS ONE, 2014
    Co-Authors: Sabine A Tanner, Annina Zihler Berner, Eugenia Rigozzi, Franck Grattepanche, Christophe Chassard, Christophe Lacroix
    Abstract:

    In vitro gut Modeling provides a useful platform for a fast and reproducible assessment of treatment-related changes. Currently, pig intestinal Fermentation Models are mainly batch Models with important inherent limitations. In this study we developed a novel in vitro continuous Fermentation Model, mimicking the porcine proximal colon, which we validated during 54 days of Fermentation. This Model, based on our recent PolyFermS design, allows comparing different treatment effects on the same microbiota. It is composed of a first-stage inoculum reactor seeded with immobilized fecal swine microbiota and used to constantly inoculate (10% v/v) five second-stage reactors, with all reactors fed with fresh nutritive chyme medium and set to mimic the swine proximal colon. Reactor effluents were analyzed for metabolite concentrations and bacterial composition by HPLC and quantitative PCR, and microbial diversity was assessed by 454 pyrosequencing. The novel PolyFermS featured stable microbial composition, diversity and metabolite production, consistent with bacterial activity reported for swine proximal colon in vivo. The constant inoculation provided by the inoculum reactor generated reproducible microbial ecosystems in all second-stage reactors, allowing the simultaneous investigation and direct comparison of different treatments on the same porcine gut microbiota. Our data demonstrate the unique features of this novel PolyFermS design for the swine proximal colon. The Model provides a tool for efficient, reproducible and cost-effective screening of environmental factors, such as dietary additives, on pig colonic Fermentation.

  • monitoring horizontal antibiotic resistance gene transfer in a colonic Fermentation Model
    FEMS Microbiology Ecology, 2011
    Co-Authors: Martina C Haug, Sabine A Tanner, Christophe Lacroix, Marc J A Stevens, Leo Meile
    Abstract:

    The human microbiota is suggested to be a reservoir of antibiotic resistance (ABR) genes, which are exchangeable between transient colonizers and residing bacteria. In this study, the transfer of ABR genes from Enterococcus faecalis to Listeria monocytogenes and to commensal bacteria of the human gut microbiota was demonstrated in a colonic Fermentation Model. In the first Fermentation, an E. faecalis donor harboring the marked 50-kb conjugative plasmid pRE25* and a chromosomal marker was co-immobilized with L. monocytogenes and infant feces. In this complex environment, the transfer of pRE25* to L. monocytogenes was observed. In a second Fermentation, only the E. faecalis donor and feces were co-immobilized. Enumeration of pRE25* and the donor strain by quantitative PCR revealed an increasing ratio of pRE25* to the donor throughout the 16-day Fermentation, indicating the transfer of pRE25*. An Enterococcus avium transconjugant was isolated, demonstrating that ABR gene transfer to gut commensals occurred. Moreover, pRE25* was still functional in both the E. avium and the L. monocytogenes transconjugant and transmittable to other genera in filter mating experiments. Our study reveals that the transfer of a multiresistance plasmid to commensal bacteria in the presence of competing fecal microbiota occurs in a colonic Model, suggesting that commensal bacteria contribute to the increasing prevalence of antibiotic-resistant bacteria.

Jérôme Bindelle - One of the best experts on this subject based on the ideXlab platform.

  • Discrepancies in microbiota composition along the pig gastrointestinal tract between in vivo observations and an in vitro batch Fermentation Model.
    Journal of animal science, 2020
    Co-Authors: Christelle Boudry, Christine Poelaert, Daniel Portetelle, André Thewis, Jérôme Bindelle
    Abstract:

    In vitro Fermentation Models are increasingly used to assess prebiotic potential of novel indigestible carbohydrates (CHO). A trial was performed to assess the validity of such approaches by comparing the influence of Fermentation of inulin and cellulose on microbiota in vivo and in vitro. Two semipurified diets based on 5% inulin or 5% cellulose were fed to 2 groups of four 25-kg pigs. After 3 wk, the pigs were slaughtered and digesta was sampled from jejunum, ileum, cecum, and 3 parts of the colon to measure pH and microbiota population. An in vitro gas Fermentation test was also performed on inulin and cellulose using fresh feces of the experimental pigs as bacterial inoculum. The gas production kinetics were Modeled and Fermentation broth sampled after 5, 8, 12, 24, and 72 h. Bacterial DNA was extracted and quantitative PCR was performed to quantify total bacteria, lactobacilli, bifidobacteria, Bacteroides, Clostridium cluster I, and Escherichia coli. Total bacteria quantification was similar between both systems. In vivo, total bacteria increased (P < 0.001) along the gut until the second part of the colon (from 10.5(7) to 10(10) cfu/mg) and then decreased (P < 0.05) to 10(9) cfu whereas in vitro, it increased (P < 0.05) until 12 to 24 h of Fermentation (from 10(9) to 10.5(9) cfu/mL) and then decreased (P < 0.05) to initial level (10(9) cfu/mL). This evolution was consistent with Fermentation kinetics. In both Models, inulin increased (P < 0.05) the ratio of bifidobacteria and E. coli populations in the total microflora compared to cellulose. However, in vivo this was observed only in the first parts of the gut whereas in vitro the effect lasted for 72 h. Inulin also increased (P < 0.001) Bacteroides genus in vitro but not in vivo where the evolutions of Bacteroides were similar (P > 0.05) for both CHO. Evolutions of lactobacilli and Clostridium populations in both systems were also not consistent. This can be ascribed to specific bacterial properties as, for example, adhesive properties or sensitivity to sulfur reducing agent used in the in vitro Model. As is, the in vitro Model does not reflect properly changes in microbiota along the digestive tract induced by specific feed ingredients compared to in vivo observations.

  • Reducing agent can be omitted in the incubation medium of the batch in vitro Fermentation Model of the pig intestines.
    Animal, 2017
    Co-Authors: Christine Poelaert, Christelle Boudry, Daniel Portetelle, André Thewis, Géraldine Nollevaux, Bernard Taminiau, Carine Nezer, Georges Daube, Yves-jacques Schneider, Jérôme Bindelle
    Abstract:

    : Over the past decade, in vitro methods have been developed to study intestinal Fermentation in pigs and its influence on the digestive physiology and health. In these methods, ingredients are fermented by a bacterial inoculum diluted in a mineral buffer solution. Generally, a reducing agent such as Na2S or cysteine-HCl generates the required anaerobic environment by releasing metabolites similar to those produced when protein is fermented, possibly inducing a dysbiosis. An experiment was conducted to study the impact of two reducing agents on results yielded by such in vitro Fermentation Models. Protein (soybean proteins, casein) and carbohydrate (potato starch, cellulose) ingredients were fermented in vitro by bacteria isolated from fresh feces obtained from three sows in three carbonate-based incubation media differing in reducing agent: (i) Na2S, (ii) cysteine-HCl and (iii) control with a mere saturation with CO2 and devoid of reducing agent. The gas production during Fermentation was recorded over 72 h. Short-chain fatty acids (SCFA) production after 24 and 72 h and microbial composition of the Fermentation broth after 24 h were compared between ingredients and between reducing agents. The Fermentation residues after 24 h were also evaluated in terms of cytotoxicity using Caco-2 cell monolayers. Results showed that the effect of the ingredient induced higher differences than the reducing agent. Among the latter, cysteine-HCl induced the strongest differences compared with the control, whereas Na2S was similar to the control for most parameters. For all ingredients, final gas produced per g of substrate was similar (P>0.10) for the three reducing agents whereas the maximum rate of gas production (R max) was reduced (P0.10) after 24 h of Fermentation with Na2S and in the control without reducing agent. Molar ratios of branched chain-fatty acids were higher (P

  • chemical characterisation and in vitro assessment of the nutritive value of co products yield from the corn wet milling process
    Food Chemistry, 2015
    Co-Authors: Christelle Boudry, Jérôme Bindelle, Paul Malumba, Olivier Roiseux, Yves Beckers, Francois Bera
    Abstract:

    The chemical characteristics of co-products recovered during a laboratory-scale wet milling procedure as well as that of whole corn flour were characterised and their digestibility and fermentability value determined using a 2 steps in vitro digestibility and Fermentation Model of the pig digestive tract. Five co-products differing in their chemical composition were collected and analysed. These co-products differed in their in vitro dry matter Digestibility and in their kinetic of Fermentation. High coefficients of digestibility were observed for starchy samples, while low coefficients of digestibility were observed for samples rich in lignocellulosic components. Fermentation patterns of samples analysed were different as well as the profile of volatile fatty acids produced during the Fermentation. The production of straight-chain fatty acids produced was significantly correlated with the proportion of starch in the sample, while branched-chain fatty acids were correlated to proteins concentration of samples.

  • Discrepancies in microbiota composition along the pig gastrointestinal tract between in vivo observations and an in vitro batch Fermentation Model
    Journal of Animal Science, 2012
    Co-Authors: Christelle Boudry, Christine Poelaert, Daniel Portetelle, André Thewis, Jérôme Bindelle
    Abstract:

    : In vitro Fermentation Models are increasingly used to assess prebiotic potential of novel indigestible carbohydrates (CHO). A trial was performed to assess the validity of such approaches by comparing the influence of Fermentation of inulin and cellulose on microbiota in vivo and in vitro. Two semipurified diets based on 5% inulin or 5% cellulose were fed to 2 groups of four 25-kg pigs. After 3 wk, the pigs were slaughtered and digesta was sampled from jejunum, ileum, cecum, and 3 parts of the colon to measure pH and microbiota population. An in vitro gas Fermentation test was also performed on inulin and cellulose using fresh feces of the experimental pigs as bacterial inoculum. The gas production kinetics were Modeled and Fermentation broth sampled after 5, 8, 12, 24, and 72 h. Bacterial DNA was extracted and quantitative PCR was performed to quantify total bacteria, lactobacilli, bifidobacteria, Bacteroides, Clostridium cluster I, and Escherichia coli. Total bacteria quantification was similar between both systems. In vivo, total bacteria increased (P 0.05) for both CHO. Evolutions of lactobacilli and Clostridium populations in both systems were also not consistent. This can be ascribed to specific bacterial properties as, for example, adhesive properties or sensitivity to sulfur reducing agent used in the in vitro Model. As is, the in vitro Model does not reflect properly changes in microbiota along the digestive tract induced by specific feed ingredients compared to in vivo observations.