Genetic diversity, cholesterol reduction, and presence of conserved bile salt hydrolase gene in probiotic strains from human milk.

Probiotics are known to possess strain and species-specific functional properties, of which hypocholesteremia is of major interest. Bile salt hydrolase (BSH) activity is one of the key mechanism involved in hypocholesterolemic effect. The study was designed to genetically characterize probiotics from human milk on the basis of Simple Sequence Repeat (SSR), isolate potent hypocholesterolemic strains, detect BSH activity, deconjugation of bile salts and bsh polymorphism. Current study, for the first-time, linked genetic diversity with cholesterol reduction potential and prove presence of conserved bsh of Levilactobacillus brevis in genetically diverse species. The strains displayed 2.78-42.23% cholesterol reduction that was not influenced by prebiotics. Data of SSR markers used in study indicated 93.3% diversity and cluster analysis distributed them in XI clades, while out of five potent cholesterol-reducing strains, three belonged to clade I. The strains could deconjugate both Sodium glyco- and taurocholate but preferred Sodium glycocholate. The variation in cholesterol reduction potential and BSH activity pointed towards presence of more than one bsh in the strains. Weissella confusa MW051433 displayed highest cholesterol reduction (42.32%) and specific BSH activity (2.64 U ml-1). Search for other bsh and in vivo assessment of cholesterol reduction by W. confusa MW051433 have been proposed.