# Distinct Gut Microbiota Profiles Reflect Severity in Chronic Insomnia Disorder

## TL;DR

This study finds that gut microbiota profiles differ based on the severity of chronic insomnia disorder, suggesting potential for microbiota-based diagnostics.

## Contribution

The study identifies distinct gut microbiota signatures associated with CID severity and evaluates their diagnostic potential.

## Key findings

- S-CID patients showed significant gut microbiota dysbiosis compared to healthy controls.
- Seven key bacterial genera were consistently correlated with sleep parameters.
- A random forest model achieved moderate efficacy in distinguishing S-CID patients via microbial signatures.

## Abstract

Severe insomnia symptoms increase the risk of persistent sleep disorders, underscoring the need for timely identification to optimize therapeutic interventions. Given the established association between chronic insomnia disorder (CID) and gut microbiota, this study aimed to evaluate the utility of gut microbiota characteristics for stratifying CID severity.

A total of 65 patients with CID were categorized into two groups based on Pittsburgh Sleep Quality Index (PSQI) scores: S‐CID (more severe poor sleep quality; median age: 36, IQR: 30–47; M/F: 12/22) and M‐CID (milder poor sleep quality; median age: 33, IQR: 25–43; M/F: 11/20). Thirty healthy controls (HC; median age: 32, IQR: 26–48; M/F: 8/22) were also included. All participants underwent polysomnography and clinical assessments. Fecal samples were collected and analyzed via 16S rRNA gene sequencing. We compared microbial structure across severity groups, identified key bacterial genera using LASSO regression and the Boruta algorithm, and examined their correlations with sleep parameters via Spearman analysis. Functional pathway predictions were performed with PICRUSt2. A random forest model was constructed to evaluate severity‐stratified discriminative capacity.

Significant alterations in gut microbial diversity and composition were observed in S‐CID patients compared to HC, whereas M‐CID patients showed less pronounced differences. Seven key bacterial genera were identified and consistently correlated with sleep parameters. Functional perturbations in glutamate/butanoate metabolism and branched‐chain amino acid degradation pathways differed by severity. The random forest model demonstrated moderate efficacy (AUC = 0.711–0.730) in distinguishing S‐CID patients based on microbial signatures.

This study reveals distinct gut microbial signatures associated with varying severity levels of CID, providing insights that may support the development of microbiota‐based diagnostic and therapeutic interventions.

The authors used 16S rRNA sequencing and PICRUSt2 analysis to explore the link between sleep quality and gut microbiota in chronic insomnia disorder (CID) patients. Those with more severe sleep disturbances exhibited pronounced gut microbiota dysbiosis (structural/functional alterations). Specific microbial profiles showed moderate efficacy in differentiating patients with poorer sleep quality.