title: Intestinal steroid profiles and microbiota composition in colitic mice.
abstract: Reduced gut microbiota diversity in conjunction with a bloom of few bacterial species is a common feature in inflammatory bowel disease (IBD) patients. However, the environmental changes caused by inflammation and their possible impact on the microbiota are largely unknown. Since IBD is associated with an impaired intestinal steroid metabolism, we hypothesized that changes in intestinal steroid and particularly bile acid (BA) concentrations affect microbial communities. We used Interleukin-10 deficient (IL-10-/-) mice as a model for chronic gut inflammation. Healthy wild-type mice served as controls. In these animals, intestinal steroid concentrations and gut microbial diversity were analyzed at 24 weeks of age. The IL 10-/- mice developed moderate inflammation in cecum and colon and colorectal tumor formation was observed in 55 % of the animals. Compared to the healthy conditions, gut inflammation was associated with higher intestinal cholesterol and cholic acid concentrations and a reduced microbial diversity. The latter was accompanied by a proliferation of Robinsoniella peoriensis, Clostridium innocuum, Escherichia coli, and Enterococcus gallinarum. All these species proved to be highly bile acid resistant. We concluded that chronic colitis in IL-10-/- mice is associated with changes in intestinal steroid profiles. These changes may be due to alterations in gut microbiota composition or vice versa. Whether the bacterial sterol and bile acid metabolism is implicated in colitis and colorectal carcinoma etiology remains to be clarified.
authors.affiliation: German Institute of Human Nutrition Potsdam-Rehbruecke Department of Gastrointestinal Microbiology Arthur-Scheunert-Allee 114-116 14558 Nuthetal, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Wohlgemuth
authors.forename: Sylvia
authors.initials: S
authors.lastname: Keller
authors.forename: Romy
authors.initials: R
authors.lastname: Kertscher
authors.forename: Mandy
authors.initials: M
authors.lastname: Stadion
authors.forename: Dirk
authors.initials: D
authors.lastname: Haller
authors.forename: Sigrid
authors.initials: S
authors.lastname: Kisling
authors.forename: Gerhard
authors.initials: G
authors.lastname: Jahreis
authors.forename: Michael
authors.initials: M
authors.lastname: Blaut
authors.forename: Gunnar
authors.initials: G
authors.lastname: Loh
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D003092:Colitis / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D016753:Interleukin-10 / Q000172:deficiency / Q000235:genetics; D007422:Intestines / Q000737:chemistry* / Q000276:immunology / Q000382:microbiology*; D008297:Male; D054892:Metagenome; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013256:Steroids / Q000032:analysis* / Q000276:immunology
chemical_list: D013256:Steroids; D016753:Interleukin-10