Daily intake of heat-killed Lactobacillus plantarum L-137 improves inflammation and lipid metabolism in overweight healthy adults: a randomized-controlled trial

PURPOSE: The effects of heat-killed Lactobacillus plantarum L-137 (HK L-137) on inflammation and lipid metabolism were investigated in overweight volunteers. METHODS: One hundred healthy subjects with a body mass index from 23.0 to 29.9 (51 men and 49 women; mean age: 41.4 years) were enrolled in this randomized, double-blind, placebo-controlled, parallel group study. Subjects were randomly assigned to daily administration of a tablet containing HK L-137 (10 mg) or a placebo tablet for 12 weeks. Blood samples were collected every 4 weeks to measure biomarkers of lipid metabolism and inflammatory mediators. RESULTS: The percent change of concanavalin A-induced proliferation of peripheral blood mononuclear cells was significantly larger in the HK L-137 group than in the control group, similar to previous studies. The decreases of aspartate aminotransferase and alanine aminotransferase over time were significantly larger in the HK L-137 group than in the control group, as were the decreases of total cholesterol, low-density lipoprotein cholesterol, and the leukocyte count at one time point. These effects of HK L-137 were stronger in the subjects with higher C-reactive protein levels. CONCLUSIONS: These findings suggest that daily intake of HK L-137 can improve inflammation and lipid metabolism in subjects at risk of inflammation.