Strain-Specific Effects of on Hypercholesterolemic Rats and Potential Mechanisms.

Hypercholesterolemia is an independent risk factor of cardiovascular disease, which is among the major causes of death worldwide. The aim of this study was to explore whether Bifidobacterium longum strains exerted intra-species differences in cholesterol-lowering effects in hypercholesterolemic rats and to investigate the potential mechanisms. SD rats underwent gavage with each strain (CCFM 1077, I3, J3 and B3) daily for 28 days. CCFM 1077 exerted the most potent cholesterol-lowering effect, followed by I3 and B3, whereas B3 had no effect in alleviating hypercholesterolemia. Divergent alleviation of different strains on hypercholesterolemia can be attributed to the differences in bile salt deconjugation ability and cholesterol assimilation ability in vitro. By 16S rRNA metagenomics analysis, the relative abundance of beneficial genus increased in the CCFM 1077 treatment group. The expression of key genes involved in cholesterol metabolism were also altered after the CCFM 1077 treatment. In conclusion, exhibits strain-specific effects in the alleviation of hypercholesterolemia, mainly due to differences in bacterial characteristics, bile salt deconjugation ability, cholesterol assimilation ability, expressions of key genes involved in cholesterol metabolism and alterations of gut microbiota.