Deconjugation of bile salts by Lactobacillus acidophilus isolates

Deconjugation of bile salts by Lactobacillus acidophilus strains isolated from men, fermented milk, and pigs resulted in precipitate halo, opaque granular white colonies, shiny precipitate halo or clear zone around the microbial colonies on bile salt-MRS agar plates depending on the type of bile salts added. None of the L.acidophilus cultures tested exhibited 7alpha-dehydroxylase activity that transforms cholate into deoxycholate. L. acidophilus SNUL020 and SNUL01 deconjugated both taurocholate (TCA) and glycocholate (GCA) at similar rates, while L. acidophilus FM01 deconjugated GCA more rapidly than TCA. Most L. acidophilus strains tested precipitated more soluble cholesterol in the media containing taurochenodeoxycholate (TCDCA) and taurodeoxycholate (TDCA) than with TCA and GCA. In the medium containing TDCA, L. acidophilus SNUL020, SNUL01, and FM01 precipitated more than 50% of soluble cholesterol. All L. acidophilus strains tested were more resistant to taurine- than to glycine-conjugated bile salts. Fecal excretions of cholesterol and deoxycholate increased slightly with acidophilus milk intake containing live cells of L. acidophilus SNUL01. (C) 2003 Elsevier Science Ltd. All rights reserved.