New role for bacterial enzyme in gut metabolism revealed

Bile acids long have been known to play a role in human metabolism. Synthesized from cholesterol in the liver, bile acids are involved in digestive processes, particularly in absorbing fat. They also are modified extensively by bacteria, which greatly expand the types of bile acids found in the host. For most of a century, scientists believed that was the end of the bile-acid story. Recent technological advances, however, have led to a greater understanding of the origins of bile acids as well as their chemical relationships to the organisms in the gut microbiome and their host.