title: Design and Investigation of PolyFermS In Vitro Continuous Fermentation Models Inoculated with Immobilized Fecal Microbiota Mimicking the Elderly Colon.
abstract: In vitro gut modeling is a useful approach to investigate some factors and mechanisms of the gut microbiota independent of the effects of the host. This study tested the use of immobilized fecal microbiota to develop different designs of continuous colonic fermentation models mimicking elderly gut fermentation. Model 1 was a three-stage fermentation mimicking the proximal, transverse and distal colon. Models 2 and 3 were based on the new PolyFermS platform composed of an inoculum reactor seeded with immobilized fecal microbiota and used to continuously inoculate with the same microbiota different second-stage reactors mounted in parallel. The main gut bacterial groups, microbial diversity and metabolite production were monitored in effluents of all reactors using quantitative PCR, 16S rRNA gene 454-pyrosequencing, and HPLC, respectively. In all models, a diverse microbiota resembling the one tested in donor's fecal sample was established. Metabolic stability in inoculum reactors seeded with immobilized fecal microbiota was shown for operation times of up to 80 days. A high microbial and metabolic reproducibility was demonstrated for downstream control and experimental reactors of a PolyFermS model. The PolyFermS models tested here are particularly suited to investigate the effects of environmental factors, such as diet and drugs, in a controlled setting with the same microbiota source.
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.
authors.forename: Sophie
authors.initials: S
authors.lastname: Fehlbaum
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Chassard
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.
authors.forename: Martina C
authors.initials: MC
authors.lastname: Haug
authors.affiliation: Danone Nutricia Research, Palaiseau, France.
authors.forename: Candice
authors.initials: C
authors.lastname: Fourmestraux
authors.affiliation: Danone Nutricia Research, Palaiseau, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Derrien
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lacroix
mesh_terms: D000368:Aged; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D003106:Colon / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D005260:Female; D005285:Fermentation; D006801:Humans; D064307:Microbiota; D008954:Models, Biological; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D012336:RNA, Ribosomal, 16S