51. Cooperative formation of omega-muricholic acid by intestinal microorganisms.
- Author
-
Eyssen H, De Pauw G, Stragier J, and Verhulst A
- Subjects
- Animals, Bile Acids and Salts metabolism, Biotransformation, Germ-Free Life, Male, Rats, Cecum microbiology, Cholic Acids metabolism, Eubacterium metabolism, Fusobacterium metabolism
- Abstract
Three anaerobic bacteria, isolated from the ceca of rats and mice, converted, through a concerted mechanism, beta-muricholic acid, the predominant bile acid in germfree rats, into omega-muricholic acid. One isolate was a Eubacterium lentum strain; the second and third isolates were tentatively identified as atypical Fusobacterium sp. strains. The conversion of beta-muricholic acid into omega-muricholic acid proceeded in two steps: E. lentum oxidized the 6 beta-hydroxyl group of beta-muricholic acid to a 6-oxo group, which was reduced by either of the two other species to a 6 alpha-hydroxyl group, yielding omega-muricholic acid. This transformation occurred both in vitro and in gnotobiotic rats. Monoassociation of germfree rats with the E. lentum strain gave rise to an unidentified fecal bile acid, probably a derivative of beta-muricholic acid having a double bond in the side chain.
- Published
- 1983
- Full Text
- View/download PDF