Bile Acid Hydrolysis Assay

Bacterial seed cultures were inoculated into 2 ml PPS medium, which contained the taurine-conjugated bile acid mixture (5 μM each) of taurocholic acid (TCA, Millipore Sigma, #86339), TβMCA (Cayman, #20289), taurochenodeoxycholic acid (TCDCA, Millipore Sigma, #T6260), THDCA (Millipore Sigma, #T0682), taurodeoxycholic acid (TDCA, Millipore Sigma, #T0875) and taurolithocholic acid (TLCA, Millipore Sigma, #T7515). These cultures were then grown overnight anaerobically at 37 °C. The entire culture was subjected to the bile acid measurement. To verify the inhibitory effects of BSH inhibitor, 10 μM C7 was added to the culture medium during inoculation. Hydrolysis efficacy was determined by the percentage of remaining conjugated bile acids in the bacterial culture medium, which was normalized with blank controls defined as 100%.