Hypnotic and sleep-promoting effects of Limosilactobacillus reuteri LM1063 on pentobarbital-induced sleep and electroencephalogram analysis in mice

Sleep disturbances are an increasing health concern, and limitations associated with long-term use of conventional hypnotics have prompted interest in alternative approaches that support sleep health. Growing evidence suggests that the gut–brain axis contributes to sleep regulation; however, the effects of probiotics on objective sleep parameters and their underlying mechanisms remain incompletely understood and may vary across probiotic strains. The present study investigated the sleep–modulating effects of a selected probiotic strain, Limosilactobacillus reuteri LM1063 (LM1063), using murine models. Sleep latency and duration were assessed using a pentobarbital-induced sleep test, and sleep architecture was evaluated by electroencephalogram (EEG) recordings, including rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. To explore potential mechanisms, neurochemical analyses focusing on key neurotransmitters, including gamma-aminobutyric acid (GABA) and serotonin, were conducted. Administration of LM1063 significantly shortened sleep latency and prolonged sleep duration in mice. EEG analysis revealed shifts in overall sleep architecture toward a sleep-favorable state without disruption of normal sleep organization. These sleep-related changes were accompanied by modulation of GABAergic and serotonergic neurochemical pathways. In conclusion, LM1063 exerts strain-specific sleep-modulating effects through neurochemical mechanisms associated with the gut–brain axis. By integrating behavioral sleep assessment, electrophysiological analysis, and neurochemical profiling, this study provides mechanistic insight supporting the potential translational application of microbiome-targeted approaches for promoting sleep health.