Sleep-promoting mechanism of Lactobacillus plantarum P8 combined with traditional Chinese medicine revealed by network pharmacology, microbiome, metabolome, and transcriptome analyses

As sleep quality improvement has become a concern in modern society, this study systematically investigated the potential sleep-promoting mechanisms of Lactobacillus plantarum P8 ( L. plantarum P8) combined with traditional Chinese medicine (TCM). Network pharmacology analysis revealed that the homologous medicine-food formula, comprising Ziziphi Spinosae Semen , Lilii Bulbus , Gardeniae Fructus , and Poria Cocos (Schw.) Wolf , may alleviate insomnia through the PI3K-AKT and Toll-like receptor pathways. Furthermore, L. plantarum P8 combined with TCM significantly increased sleep duration , reduced sleep latency, and improved sleep rate ( P < 0.05). L. plantarum P8 combined with TCM exhibited neuroprotective effects by enhancing the release of 5-HT and GABA in brain tissue. Gut microbiota analyses indicated that while maintaining the Firmicutes to Bacteroidota ratio, the L. plantarum P8 combined with TCM intervention promoted the abundance of sleep-inducing bacteria, particularly Oscillibacter . Metabolomic profiling suggested that the sleep-promoting effect of L. plantarum P8 combined with TCM may be related to short-chain fatty acids (SCFAs), pyruvate , and phosphocreatine . Transcriptomic analysis elucidated that sleep-promoting was mainly related to the cAMP signalling and dopaminergic synapse pathways. Spearman's correlation analysis showed that gut microbiota significantly correlated with neurotransmitters , SCFAs, genes, and metabolites. Metabolome-transcriptome analyses revealed that L. plantarum P8 combined with TCM promoted sleep mainly through lipid and amino acid metabolism . This study provides mechanistic insights into the synergistic sleep-promoting effects of L. plantarum P8 combined with TCM, providing a scientific reference for the development of probiotics combined with TCM therapies in sleep management. • L. plantarum P8 can synergise with TCM for sleep-promoting. • L. plantarum P8 combined with TCM increased inhibitory neurotransmitter levels. • The effect of L. plantarum P8 combined with TCM on gut microbiota was clarified. • Sleep-promoting metabolites in serum were screened by untargeted metabolomics. • Sleep-promoting genes in the brain were identified by transcriptomics.