title: Incorporating a mucosal environment in a dynamic gut model results in a more representative colonization by lactobacilli.
abstract: To avoid detrimental interactions with intestinal microbes, the human epithelium is covered with a protective mucus layer that traps host defence molecules. Microbial properties such as adhesion to mucus further result in a unique mucosal microbiota with a great potential to interact with the host. As mucosal microbes are difficult to study in vivo, we incorporated mucin-covered microcosms in a dynamic in vitro gut model, the simulator of the human intestinal microbial ecosystem (SHIME). We assessed the importance of the mucosal environment in this M-SHIME (mucosal-SHIME) for the colonization of lactobacilli, a group for which the mucus binding domain was recently discovered. Whereas the two dominant resident Lactobacilli, Lactobacillus mucosae and Pediococcus acidilactici, were both present in the lumen, L. mucosae was strongly enriched in mucus. As a possible explanation, the gene encoding a mucus binding (mub) protein was detected by PCR in L. mucosae. Also the strongly adherent Lactobacillus rhamnosus GG (LGG) specifically colonized mucus upon inoculation. Short-term assays confirmed the strong mucin-binding of both L. mucosae and LGG compared with P.acidilactici. The mucosal environment also increased long-term colonization of L. mucosae and enhanced its stability upon antibiotic treatment (tetracycline, amoxicillin and ciprofloxacin). Incorporating a mucosal environment thus allowed colonization of specific microbes such as L. mucosae and LGG, in correspondence with the in vivo situation. This may lead to more in vivo-like microbial communities in such dynamic, long-term in vitro simulations and allow the study of the unique mucosal microbiota in health and disease.
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors: Pieter
authors: P
authors: Van den Abbeele
authors: Stefan
authors: S
authors: Roos
authors: Venessa
authors: V
authors: Eeckhaut
authors: Donald A
authors: DA
authors: MacKenzie
authors: Melanie
authors: M
authors: Derde
authors: Willy
authors: W
authors: Verstraete
authors: Massimo
authors: M
authors: Marzorati
authors: Sam
authors: S
authors: Possemiers
authors: Barbara
authors: B
authors: Vanhoecke
authors: Filip
authors: F
authors: Van Immerseel
authors: Tom
authors: T
authors: Van de Wiele
mesh_terms: D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D007778:Lactobacillus / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D008954:Models, Biological; D010802:Phylogeny