Absence of cecal secondary bile acids in gnotobiotic mice associated with two human intestinal bacteria with the ability to dehydroxylate bile acids in vitro

Abstract

Germ-free mice were orally inoculated with human intestinal 7α- dehydroxylating bacterial strains to evaluate their ability to transform bile acids in vivo. Three weeks after inoculation of the bacteria, cecal bile acids were examined. Among free-form bile acids, only β-muricholic acid was detected in the cecal contents of gnotobiotic mice associated with Bacteroides distasonis strain K-5. No secondary bile acid was observed in the cecal contents of any of the gnotobiotic mice associated with 7α- dehydroxylating bacteria, Clostridium species strain To-931 or Eubacterium species strain 36s.