Characterization of Lactobacillus plantarum Lp27 isolated from Tibetan kefir grains: a potential probiotic bacterium with cholesterol-lowering effects.

Lactobacillus plantarum Lp27 was isolated from Tibetan kefir grains. The Lp27 isolate survived a 3-h incubation at pH 2.0 and grew normally in 0.3% oxgall. In addition, the Lp27 isolate exhibited an adhesion ratio of 9.5 ± 2.5% with Caco-2 cells. Antibiotic susceptibility tests indicated that the Lp27 isolate was sensitive to gentamicin, tetracycline, erythromycin, and chloramphenicol, and was resistant to vancomycin with a minimum inhibitory value of 23µg/mL. The Lp27 isolate inhibited cholesterol absorption through downregulation of Niemann-Pick C1-like 1 (NPC1L1) expression in Caco-2 cells. The Lp27 isolate was fed to hypercholesterolemic rats at a dose of 10(9) cfu/d for 4wk. The Lp27 feeding significantly lowered serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides concentrations, but no change was observed in the serum high-density lipoprotein cholesterol concentrations. In addition, liver total cholesterol and triglycerides were decreased in the Lp27-fed group. The expression of NPC1L1 in the duodenum and jejunum was significantly decreased following Lp27 feeding. These results indicate that Lp27 might be an effective cholesterol-lowering probiotic and a possible mechanism for the cholesterol-reducing effects of probiotics.