title: Epimerization of chenodeoxycholic acid to ursodeoxycholic acid by Clostridium baratii isolated from human feces.
abstract: Ursodeoxycholic acid-producing bacteria are of clinical and industrial interest due to the multiple beneficial effects of this bile acid on human health. This work reports the first isolation of 7-epimerizing bacteria from feces of a healthy volunteer, on the basis of their capacity to epimerize the primary bile acid, chenodeoxycholic acid, to ursodeoxycholic acid. Five isolates were found to be active starting from unconjugated chenodeoxycholic acid and its tauro-conjugated homologue, but none of these strains could epimerize the glyco-conjugated form. Biochemical testing and 16S ribosomal DNA sequencing converged to show that all five isolates were closely related to Clostridium baratii (99% sequence similarity), suggesting that this bacterial species could be responsible at least partially, for this bioconversion in the human gut.
authors.affiliation: Unité d'Ecologie et de Physiologie du Système Digestif, Institut National de la Recherche Agronomique, Domaine de Vilvert, 78352 Jouy-en-Josas Cedex, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Lepercq
authors.forename: Philippe
authors.initials: P
authors.lastname: Gérard
authors.forename: Fabienne
authors.initials: F
authors.lastname: Béguet
authors.forename: Pierre
authors.initials: P
authors.lastname: Raibaud
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Grill
authors.forename: Purification
authors.initials: P
authors.lastname: Relano
authors.forename: Chantal
authors.initials: C
authors.lastname: Cayuela
authors.forename: Catherine
authors.initials: C
authors.lastname: Juste
mesh_terms: D000368:Aged; D002635:Chenodeoxycholic Acid / Q000737:chemistry / Q000378:metabolism*; D003013:Clostridium / Q000302:isolation & purification / Q000378:metabolism*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007536:Isomerism; D008297:Male; D014580:Ursodeoxycholic Acid / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002635:Chenodeoxycholic Acid; D014580:Ursodeoxycholic Acid