TITLE:
Safety Evaluation of Excessive Intake of Lactococcus lactis Subsp. lactis JCM 5805: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Trial
AUTHORS:
Yukiko Kato, Masaya Kanayama, Shu Yanai, Hajime Nozawa, Osamu Kanauchi, Satoru Suzuki
KEYWORDS:
Lactic Acid Bacteria, Lactococcus lactis, Excessive Intake, Safety
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.9 No.4,
April
30,
2018
ABSTRACT: Background/Aims: Administration of a lactic acid bacterial strain, Lactococcus lactis subsp. lactis JCM 5805 (LC-Plasma), is reported to prevent viral infection via activation of plasmacytoid dendritic cells in mouse and human studies. As it is assumed that LC-Plasma is taken in excess when it is commercially provided as a supplement, we conducted a trial using capsules to give 250 mg LC-Plasma (5 times the effective anti-viral dose) every day for four weeks to healthy volunteers to investigate the safety of excessive intake of LC-Plasma. Trial Design: A randomized, double-blind, placebo-controlled, parallel-group trial was conducted. Methods: Forty healthy subjects were randomly assigned to the LC-Plasma group (daily intake of five capsules containing 50 mg heat-killed LC-Plasma cells per capsule) or the placebo group (daily intake of five placebo capsules with no LC-Plasma). Physical, hematological, biochemical and urinary examinations and medical interviews were used to evaluate safety. Results: No abnormal differences were observed after excessive intake of LC-Plasma capsules when compared to the intake of placebo capsules. Conclusions: There are no safety concerns associated with the excessive intake of heat-killed LC-Plasma capsules.