Bile tolerance, taurocholate deconjugation and cholesterol removal by Lactobacillus acidophilus and Bifidobacterium spp.

Abstract

Six strains of L. acidophilus and nine strains of different species from the genus Bifidobacterium differed in their tolerance to bile, deconjugation of sodium taurocholate and ability to lower cholesterol concentration in the culture broth. For both L. acidophilus and bifidobacteria the rate of taurocholate deconjugation was highest at the exponential growth phase. The differences in cholesterol-lowering effect were not related to small variations in cell growth in the presence of taurocholate, to cholic acid concentration in the supernatant or to the final pH of the culture broth. Removal of cholesterol by L. acidophilus cultures was not correlated with their tolerance to bile, but a weak negative correlation (r=-0.67) was observed between inhibition of Bifidobacterium spp. cultures by bile and their cholesterol-lowering effect.