naa a22 4500 52878613X 20180924065500.0 cr unu---uuuuu 180924e20131030xx s 000 0 eng 10.3929/ethz-b-000074689 doi 10.1371/journal.pone.0077772 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/74689 Novel Polyfermentor Intestinal Model (PolyFermS) for Controlled Ecological Studies: Validation and Effect of pH [Elektronische Daten] [Annina Zihler Berner, Susana Fuentes, Alexandra Dostal, Amanda N. Payne, Pamela Vazquez Gutierrez, Christophe Chassard, Franck Grattepanche, Willem M. De Vos, Christophe Lacroix] PLoS ONE Open access ethresearch In vitro gut fermentation modeling offers a useful platform for ecological studies of the intestinal microbiota. In this study we describe a novel Polyfermentor Intestinal Model (PolyFermS) designed to compare the effects of different treatments on the same complex gut microbiota. The model operated in conditions of the proximal colon is composed of a first reactor containing fecal microbiota immobilized in gel beads, and used to continuously inoculate a set of parallel second-stage reactors. The PolyFermS model was validated with three independent intestinal fermentations conducted for 38 days with immobilized human fecal microbiota obtained from three child donors. The microbial diversity of reactor effluents was compared to donor feces using the HITChip, a high-density phylogenetic microarray targeting small subunit rRNA sequences of over 1100 phylotypes of the human gastrointestinal tract. Furthermore, the metabolic response to a decrease of pH from 5.7 to 5.5, applied to balance the high fermentative activity in inoculum reactors, was studied. We observed a reproducible development of stable intestinal communities representing major taxonomic bacterial groups at ratios similar to these in feces of healthy donors, a high similarity of microbiota composition produced in second-stage reactors within a model, and a high time stability of microbiota composition and metabolic activity over 38 day culture. For all tested models, the pH-drop of 0.2 units in inoculum reactors enhanced butyrate production at the expense of acetate, but was accompanied by a donor-specific reorganization of the reactor community, suggesting a concerted metabolic adaptation and trigger of community-specific lactate or acetate cross-feeding pathways in response to varying pH. Our data showed that the PolyFermS model allows the stable cultivation of complex intestinal microbiota akin to the fecal donor and can be developed for the direct comparison of different experimental conditions in parallel reactors continuously inoculated with the exact same microbiota. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Zihler Berner Annina joint author Fuentes Susana joint author Dostal Alexandra joint author Payne Amanda N. joint author Vazquez Gutierrez Pamela joint author Chassard Christophe joint author Grattepanche Franck joint author De Vos Willem M. joint author Lacroix Christophe joint author PLoS ONE San Francisco, CA, USA : Public Library of Science 8 (10), p. e77772 1932-6203 http://hdl.handle.net/20.500.11850/74689 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/74689 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Zihler Berner Annina joint author ETHRESEARCH 700 1- Fuentes Susana joint author ETHRESEARCH 700 1- Dostal Alexandra joint author ETHRESEARCH 700 1- Payne Amanda N. joint author ETHRESEARCH 700 1- Vazquez Gutierrez Pamela joint author ETHRESEARCH 700 1- Chassard Christophe joint author ETHRESEARCH 700 1- Grattepanche Franck joint author ETHRESEARCH 700 1- De Vos Willem M. joint author ETHRESEARCH 700 1- Lacroix Christophe joint author ETHRESEARCH 773 0- PLoS ONE San Francisco, CA, USA : Public Library of Science 8 (10), p. e77772 1932-6203 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access