Purpose: The major purpose of this study was to detect the changes in gut microbiota composition and inflammatory cytokines production associated with acute and chronic insomnia. This study also evaluated the relationship between gut microbiota changes and increased inflammatory cytokines in insomnia patients.
Patients and Methods: Outpatients with acute and chronic insomnia (aged 26– 55 years; n=20 and 38, respectively) and age/gender-matched healthy controls (n=38) were recruited from a southern China region. Participants’ gut microbiome, plasma cytokines, and self-reported sleep quality and psychopathological symptoms were measured.
Results: The gut microbiomes of insomnia patients compared with healthy controls were characterized by lower microbial richness and diversity, depletion of anaerobes, and short-chain fatty acid (SCFA)-producing bacteria, and an expansion of potential pathobionts. Lachnospira  and Bacteroides  were signature bacteria for distinguishing acute insomnia patients from healthy controls, while Faecalibacterium  and Blautia  were signature bacteria for distinguishing chronic insomnia patients from healthy controls. Acute/chronic insomnia-related signature bacteria also showed correlations with these patients’ self-reported sleep quality and plasma IL-1β.
Conclusion: These findings suggest that insomnia symptomology, gut microbiota, and inflammation may be interrelated in complex ways. Gut microbiota may serve as an important indicator for auxiliary diagnosis of insomnia and provide possible new therapeutic targets in the field of sleep disorders.
Keywords: acute insomnia, chronic insomnia, gut microbiome, inflammatory cytokines, random forest