Metabolism of beta-muricholic acid in man.

Labeled beta-muricholic acid was obtained from germfree rats given [24-14C]-chenodeoxycholic acid. It was crystallized with the same unlabeled bile acid extracted from germfree rat pooled biles. Five patients fitted with a T-tube after cholecystectomy were given orally 100 mg of the bile acid. Metabolites of beta-muricholic acid in bile, urine and feces were studied. Glyco- and tauro-beta-muricholic acid were the only metabolites detected in bile. The urinary bile acid pattern was complex and included free, glyco- and sulfoconjugated beta-muricholic acid, but no glucuronide was observed. Analysis of fecal bile acid showed very few metabolites: the 3 beta-epimer was identified; the 6 beta- and 7 beta-hydroxyls were apparently not transformed by human intestinal microflora.