Sishen wan modulates gut microbial and short-chain fatty-acid imbalances and ameliorates behavioral and inflammatory abnormalities in mice with chronic sleep deprivation.

Background: Chronic sleep deprivation (CSD) disrupts mood-related behavior, gut microbial ecology, and inflammatory homeostasis. Sishen Wan (SSW), a medicinal plant formula used clinically for chronic diarrhea, has shown microbiota- and inflammation-modulating effects in colitis models, but its protective effects under sleep-deprivation conditions remain unclear. Methods: The chemical profile of SSW was characterized by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Male C57BL/6 J mice underwent CSD using a modified multiple-platform method and received three doses of SSW or fluoxetine. Behavioral performance, histopathology, gut microbiota composition, and short-chain fatty acid (SCFA) concentrations in feces, serum, and hippocampal tissue were assessed. Fecal material from Control, Model, and high-dose SSW (SSW-H) donors was transplanted into antibiotic-pretreated recipients. Serum untargeted metabolomics, hippocampal transcriptomics, RT-qPCR, and resting-state functional magnetic resonance imaging were used to characterize metabolic, transcriptional, and brain-function changes. Results: CSD reduced sucrose preference and open-field activity, prolonged immobility in the tail-suspension and forced-swim tests, aggravated colonic and hippocampal injury, and increased pro-inflammatory cytokines. SSW-H produced the most consistent improvements. CSD also reduced gut microbial richness and diversity, altered community composition, and lowered fecal acetate, propionate, and butyrate and serum acetate. SSW-H shifted the community toward the Control profile, increased Akkermansia, reduced several Model-enriched taxa, and increased major fecal SCFAs and serum acetate. Recipients of Model-donor feces developed reduced sucrose preference and activity, prolonged immobility, and colonic and hippocampal abnormalities. In contrast, recipients of SSW-H-donor feces showed milder behavioral and histological changes and a microbial profile distinct from that of FMT-Model recipients. SSW-H was also associated with partial normalization of lipid-, amino-acid-, and one-carbon-metabolism-related serum features, modulation of hippocampal immune pathways involving chemokines, cytokines, and NF-κB signaling, and attenuation of several CSD-associated regional brain abnormalities. Conclusion: SSW alleviated CSD-associated behavioral abnormalities, tissue injury, and inflammation, with the high dose showing the most consistent effects. These improvements were accompanied by changes in gut microbial composition and SCFA profiles.