Effect of orally administered heat-treated Lactobacillus plantarum LM1004 on the innate immune system: A randomized, placebo-controlled, double-blind study

Heat-treated Lactobacillus plantarum LM1004 (HT-LM1004) isolated from Korean kimchi and further processed has been reported to exert the stimulatory activities on the innate immune system in our previous in vitro and in vivo studies. The aim of the present study was to examine the effect of HT-LM1004 on changes in natural killer (NK) cell activity, the serum concentrations of cytokines and safety parameters in healthy adults aged 19-75 years. In the present randomized, placebo-controlled, double-blind trial, one hundred subjects consumed a capsule containing 2 x 1010 cells of HT-LM1004 or placebo once per day over eight weeks. Significant increases in NK cell activity (%) were observed in the treatment group after eight weeks of HT-LM1004 ingestion compared to the control group (p = 0.036). This study also demonstrated a consistent trend of enhanced serum level of interleukin (IL)-12 by dietary intake of HT-LM1004 without any side effects.

Automated summary

This study demonstrates that ingestion of heat-treated Lactobacillus plantarum LM1004 can significantly increase natural killer cell activity and enhance serum levels of interleukin-12 without any side effects.