Lactobacillus crispatus KT-11 strain: its safety and effects on alleviating pollinosis

摘要

We previously reported that the oral administration of Lactobacillus crispatus KT-11 strain (KT-11) in mouse models of atopic dermatitis and allergic rhinitis reduced allergy symptoms. In this study, we investigated the effects of KT-11 consumption on pollinosis symptoms in humans. A double-blind, three-group comparison study was conducted in healthy volunteers with symptoms of pollinosis. Participants consumed either a test food (a tablet that contained 0.2 x 10~11 or 1.0 x 10~11 KT-11 cells) or a placebo food (a tablet without KT-11) every day for 12 weeks from January to April 2013. The safety of KT-11 consumption was evaluated by blood and urine tests and interviews with a physician, and pollinosis symptoms were assessed according to the Practical Guideline for the Management of Allergic Rhinitis. The groups that consumed KT-11 showed no significant difference in the blood and urine test results before and after KT-11 consumption, and no adverse events were observed. However, the pollinosis symptom scores (nasal congestion, itchy eyes and hindrance in every life scores) decreased in both KT-11 groups when compared to the placebo group. Moreover, while the blood eosinophil count significantly increased after consumption when compared to before consumption in the placebo group, no significant difference before and after KT-11 consumption was observed in the KT-11 groups. These results suggest that KT-11 consumption is safe and can alleviate pollinosis symptoms through the suppression of increases in eosinophil levels.