Researchers in the Republic of Korea reported that supplementation with the strain increased sleep duration, stage 2 and REM sleep, and decreased wakefulness.
“These findings indicate that strain-defined probiotic could be used as a nutritional approach for sleep health, particularly for targeting sleep fragmentation and maintenance,” they wrote in the journal Nutrients.
Sleep continuity is an increasing problem in modern societies, due to irregular sleep-wake rhythms, nighttime use of electronic devices, stress, and consumption of stimulants such as alcohol and caffeine. Poor sleep and wakefulness can impact performance, mental health and risk of chronic diseases.
How probiotics may support sleep
Growing evidence suggests that the gut microbiota may influence sleep through mechanisms including the gut-brain axis, tryptophan–serotonin–melatonin pathways, and gamma-aminobutyric acid (GABA)-related signaling.
Preclinical animal studies of B. coagulans IDCC 1201 have reported sleep-promoting effects through GABA signaling. The current study, however, found no significant differences in GABA blood concentrations between groups after four weeks. Still, the researchers hypothesized potential physiological and methodological reasons, noting “this null biomarker result should be interpreted cautiously and does not necessarily negate neurobiological relevance.”
The study also highlighted “practical and scientific advantages” of B. coagulans IDCC 1201 compared to other food/ botanical/fermented functional ingredients for sleep support.
“First, botanical extracts can show batch-to-batch variability owing to differences in raw materials, harvest conditions, and extraction processes, and the active constituents responsible for sleep effects are not always clearly defined,” the researchers noted, stating that a strain-defined microbial ingredient such as B. coagulans IDCC 1201 has a tighter standardization and reproducibility.
In addition, the probiotic is stable during storage and manufacturing, “supporting consistent delivery,” and, rather than just benefiting sleep initiation, as some botanicals have been found to do, it supports sleep maintenance and consolidation.
“Taken together, these results support B. coagulans IDCC 1201 as a reproducible sleep-related functional ingredient with objectively verified improvements in sleep continuity,” the researchers wrote.
Study details
The randomized, double-blind, placebo-controlled study involved 80 healthy adult participants with sleep disturbances, but without insomnia. They were randomly assigned to receive a daily probiotic capsule containing B. coagulans IDCC 1201 or a placebo for four weeks. The probiotic was provided by Ildong Bioscience Co., Ltd, which funded the study.
The researchers assessed dietary intake, anthropometrics, sleep questionnaire scales, objective sleep outcomes using polysomnography (PSG), and serum GABA concentrations.
The findings revealed that, after four weeks, compared to placebo, the probiotic significantly improved objective sleep continuity and self-reported sleep outcomes, significantly increasing sleep efficiency and duration, as well as stage 2 and REM sleep. In addition, no safety concerns were identified.
There were no detectable between-group differences in blood GABA levels, which the researchers noted could be due to sleep-relevant changes occurring centrally or locally within the gut–brain axis without a corresponding increase in peripheral GABA, immune mediators affecting sleep independently of circulating GABA, and the methods of blood sampling not fully capturing changes.
The researchers noted their study limitations, including a predominantly female population, a relatively short intervention period, and a lack of microbiome profiling, which may strengthen future understanding of mechanisms at play.
Source: Nutrients; doi: 10.3390/nu18101525; “Efficacy and Safety of Bacillus coagulans IDCC 1201 for Sleep Improvement in Adults with Sleep Disturbance: A Randomized, Double-Blind, Placebo-Controlled Polysomnographic Study.” Authors: H. Kim et al.
