Effects of lactic acid bacteria-containing foods on the quality of sleep: a placebo-controlled, double-blinded, randomized crossover study

摘要

Background: There are various types of sleep disorders, such as insomnia, hypersomnia, and rhythm disorder, which are attributed to diverse and complex background factors. Recently, many studies have reported that lactic acid bacteria, bifidobacteria, and lactoferrin, are related to fatigue and sleep. Considering these factors, we prepared test food samples containing lacticacid bacteria ingredients (fermentation products, living bacteria, and ground bacteria) derived from the lactic acid bacterium strain Lactobacillus helveticus MIKI-020 (LBH MIKI-020) and theanine, which is known to have a relaxing effect. We then tested and observed the effects of lactic acid bacteria on the quality of sleep.Methods: In this placebo-controlled, double-blinded, randomized crossover study, we randomly selected 40 male and female subjects (aged 20-64 years) to consume four-weeks test food (lactic acid bacteria ingredients –containing) tablets and placebo control food. The physical examination and laboratory test, sleep electroencephalography, Oguri-Shirakawa-Azumi sleep questionnaire (OSA sleep questionnaire), Pittsburgh Sleep Quality Index (PSQI), and Visual Analogue Scale (VAS) questionnaire were measured.Results: Sleep electroencephalography: the intergroup comparison in changes of the sleep efficiency (SE) until the 4th week showed a significant increase (improvements) compared with the placebo control food group. Furthermore, SE was compared within the group. In the test food group, the SE increased (improved) significantly in 4 weeks. OSA sleep questionnaire: in intragroup analyses between 0 and 4 weeks, significant increases (improvements) were found in the test food group. PSQI: in intragroup comparisons between week 0 and week 4, significant decreases (improvements) were found in the test food group. VAS questionnaire: the intergroup comparison in changes of Feeling of physical fatigue, Motivation (liveliness), and Calmness until the 4th week showed significant decreases (improvements) compared with placebo control food group.Conclusion: The sleep efficiency (SE) and Feeling of physical fatigue, Motivation (liveliness), and Calmness were improved by continuous consumption of test food (lactic acid bacteria- containing food). Among various sleep disorders, a large population in Japan has trouble with sleeping quality. Accordingly, consumption of lactic acid bacteria-containing foods can be a safe and effective method to improve sleep quality.