Hypocholesterolemic effects of Lactobacillus plantarum KCTC3928 by increased bile acid excretion in C57BL/6 mice

ObjectiveWe doubly coated Lactobacillus plantarum KCTC3928 with proteins and polysaccharide compounds to enhance its acid and bile resistance. The present study investigated the hypocholesterolemic effects of double-coated L. plantarum KCTC3928 in C57BL/6 mice fed a high-fat diet. The effects of live and dead bacteria were compared.MethodsSix-week-old C57BL/6 male mice were divided into three groups: the control group was fed no L. plantarum KCTC3928, and the two treatment groups were orally fed live or dead L. plantarum KCTC3928 daily. Plasma and liver cholesterol and lipid levels, fecal bile acid, and gene and protein expressions were measured.ResultsLow-density lipoprotein cholesterol and plasma triacylglycerol levels were significantly lower in the group fed live bacteria, by 42% and 32%, respectively (P < 0.05), and fecal bile acid excretion was accelerated (+45%). Expression of the low-density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase were marginally affected by the feeding of coated cells; however, the gene expression and protein levels of CYP7A1 were significantly upregulated after live L. plantarum KCTC3928 feeding (+80% for mRNA and +60% for protein expression).ConclusionDouble-coated live L. plantarum KCTC3928 may have hypocholesterolemic effects in mice primarily due to induction of fecal bile acid secretion followed by increased degradation of hepatic cholesterol into bile acids. Studies in humans should confirm the effects in the future.