Deconjugation of bile acids by intestinal bacteria: review of literature and additional studies.

Abstract

Bile acids occur in bile conjugated with glycine or taurine. Owing to their detergent property, they play an important role in absorption of fat from the gut. The 3 major bile acids are cholic, chenodeoxycholic, and deoxycholic acids. The conjugates are split by the action of the normal flora of the large bowel, and usually only free bile acids are found in the feces [1, 2]. Under abnormal conditions resulting in bacterial overgrowth in the small intestine, such as the blind loop syndrome, conjugated bile acids are split in the small bowel and fat absorption is thus impaired because of the reduction of conjugated bile salts below the level necessary for normal fat absorption [3, 4]. There has been much interest in the deconjugation of bile acids by bacteria in recent years [5-11], and several reports indicate that anaerobes normally found in intestinal flora are particularly active [5, 6, 8-10, 12]. The major components of the intestinal flora are Bacteroides and Bifidobacterium [13-15], gram-negative and gram-positive nonsporulating anaerobic bacilli, respectively. These 2 groups of organisms, as well as certain other anaerobes and some aerobes