Specificity of bile salt sulfatase activity in man, mouse and rat intestinal microflora.

Desulfation of bile acid 3-, 7- and 12-monosulfates was studied in incubates of fecal flora of man, rat and mouse. In anaerobic incubates, the 3 alpha-sulfates of the 5 beta-bile acids chenodeoxycholic acid and cholic acid, as well as the 3 alpha-sulfate of the 5 alpha-bile acid allochenodeoxycholic acid, were desulfated and further metabolized with the formation of a variety of metabolites. Desulfation yields were low in aerobically incubated samples, and aerobic subcultures were always negative. The 7- or 12-monosulfate esters of chenodeoxycholic acid and cholic acid were not hydrolyzed, neither anaerobically nor aerobically. High numbers (10(7) per 10(9) total count) of bile salt 3-sulfatase producing bacteria were present in rat cecal contents. No desulfating bacteria were detected in the proximal or medium small intestine of the rat, whereas low numbers were found in 2 out of 5 samples from the distal small intestine. These results reflect the predominantly anaerobic character of the bile salt sulfatase producing microflora in the intestine and suggest that the intestinal microflora of man, rat and mouse do not possess bile salt 7- or 12-sulfatase activity.