Sleep-promoting effects and mechanisms of Bacillus coagulans IDCC 1201: evidence from pentobarbital-induced sleep and electroencephalography analysis in mice

Abstract

Recent studies have explored the potential of probiotics to modulate sleep, particularly via neurotransmitter pathways. Bacillus coagulans IDCC 1201 is a high γ-aminobutyric acid (GABA)-producing strain, second only to Lactobacillus johnsonii IDCC 9203. This study investigated the sleep-promoting efficacy of B. coagulans IDCC 1201 using a pentobarbital-induced sleep model and electroencephalography (EEG)-based sleep architecture analysis. In the pentobarbital-induced sleep test, B. coagulans IDCC 1201 at ≥1 × 10⁸ CFU per day significantly reduced sleep latency and increased sleep duration, showing comparable efficacy to doxepin hydrochloride. Mechanistic studies revealed that the sleep-promoting effects were abolished when it was co-administered with flumazenil, a GABA_A benzodiazepine receptor antagonist, thereby supporting its action via the GABAergic system. Furthermore, a long-term EEG study demonstrated that B. coagulans IDCC 1201 administration led to a sustained increase in non-rapid eye movement sleep without affecting the stability of wakefulness. In contrast to zolpidem, which showed diminished efficacy over time, B. coagulans IDCC 1201 maintained its sleep-promoting effects over three weeks of administration without any signs of tolerance or withdrawal. Delta activity analysis indicated no adverse effects on sleep quality. These findings suggest that B. coagulans IDCC 1201 enhances sleep by modulating the GABAergic system and improving sleep architecture, highlighting its potential as a functional ingredient for sleep enhancement without the drawbacks of conventional sleep aids.