Effect of ursodeoxycholic and chenodeoxycholic acid therapy in patients with cholesterol gallstones on intestinal microflora and its bile-acid-metabolizing activity

The in vitro transformation of chenodeoxycholic (CDCA), ursodeoxycholic (UDCA), and 7-keto-lithocholic (6-keto-LCA) acid by fecal specimens from five patients with cholesterol gallstones, treated with UDCA and CDCA, and five healthy control subjects was compared. Degradation of CDCA, UDCA, and 7-keto-LCA to lithocholic acid (LCA) was generally faster in fecal cultures of treated patients than in those of controls; this finding correlates with the significantly greater number of microorganisms found to be able to produce LCA from both CDCA and UDCA. Comparative analysis of intestinal microflora composition in the two groups indicates that only the number of bifidobacteria, Gram-positive anaerobic cocci, and coliforms is increased in patients compared with normal, untreated subjects.