Related Experiment Video
Updated: Oct 17, 2026
Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport
Published on: November 27, 2016
Isolation and characterization of cholic acid 7alpha-dehydroxylating fecal bacteria from cholesterol gallstone
J E Wells1, F Berr, L A Thomas
1Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond 23298-0678, USA.
Background/Aims:
The development of cholesterol gallstones, in some patients, has been associated with increased proportions of deoxycholic acid in the bile acid pool. Deoxycholic acid is a microbial product of cholic acid 7alpha-dehydroxylation in the intestines. The levels and activities of bile acid 7alpha-dehydroxylating bacteria have been reported to be increased in gallstone patients. The aim of the current study was to isolate 7alpha-dehydroxylating bacteria from gallstone patients and determine if these individuals are colonized by similar bacterial species.
Methods:
The levels of 7alpha-dehydroxylating bacteria in fecal samples were determined by fecal dilutions in 24 gallstone patients and 10 controls. 7alpha-Dehydroxylating bacteria were isolated by a non-selective streak plate technique and 7alpha-dehydroxylation activity was determined by measuring the conversion of [14C]-cholic acid to [14C]-deoxycholic acid using thin-layer chromatography.
Results:
Gallstone patients had >42-fold (p<0.01) higher levels of 7alpha-dehydroxylating bacteria than patients who had not developed gallstones. Eighteen strains of 7alpha-dehydroxylating bacteria were isolated from eight gallstone patients. Attempts to isolate 7alpha-dehydroxylating bacteria from ten control patients were unsuccessful using identical isolation techniques. Surprisingly, all strains of bacteria isolated from gallstone patients appear to belong to the genus Clostridium.
Conclusion:
Gallstone patients have higher levels of 7alpha-dehydroxylating fecal bacteria and appear to harbor only members of the genus Clostridium with this activity.
