薬理と治療

Abstract

Background　Daily intake of heat-killed Lactobacillus plantarum L-137（HK L-137）augmented acquired immunity and improved health-related quality of life in healthy adults. However, effects of HK L-137 on natural immunity and specific symptoms are poorly understood. Therefore, we investigated the effects of HK L-137 on monocyte phenotype and immune-related symptoms in high immunological responders who could readily respond to immunostimulants such as HK L-137. Methods　We reanalyzed our published data from a randomized, double-blind, placebo-controlled trials in sixty healthy participants（mean age 56.3 y）（J Nutr 2006; 136: 3069-73）and performed a stratified analysis by using concanavalin A-induced proliferation of peripheral blood mononuclear cells（PBMC）. In the study, participants took a capsule with 10 mg HK L-137（HK L-137 group, n＝30）or without HK L-137（placebo group, n＝30）daily for 12 weeks, and we examined monocyte CD64 expression and immune- and common cold-related symptoms in high immunological responders（participants with PBMC proliferation values in the upper half at baseline）. Results　In the high immunological responders, the percent change from baseline in expression of CD64 on monocytes at week 8 and the degrees of improvement in immune-and common cold-related symptoms at week 8 and at week 12 were significantly higher in the HK L-137 group than in the placebo group（P＜0.05）. Conclusions　These results suggest that a daily intake of HK L-137 augments natural immunity in the high immunological responders, thereby improving the immune-related symptoms.（Jpn Pharmacol Ther 2022；50：1861‒70）