The gut microbial composition is different in chronic fatigue syndrome than in healthy controls.
Prylińska-Jaśkowiak, Monika, Tabisz, Hanna, Kujawski, Sławomir et al. · Scientific reports · 2025 · DOI
Quick Summary
Researchers compared the bacteria living in the gut of people with ME/CFS to healthy people and found clear differences. People with ME/CFS had less diverse bacterial communities and different types of bacteria overall. A computer program could accurately tell the difference between ME/CFS and healthy people just by looking at their gut bacteria patterns, suggesting this difference might be important for the illness.
Why It Matters
Identifying consistent microbiota differences between ME/CFS patients and healthy controls provides objective biological markers that could support diagnosis and suggests the gut microbiome may be involved in disease pathogenesis. This opens new avenues for investigating whether modifying gut bacteria could be therapeutic for ME/CFS patients.
Observed Findings
Significantly lower bacterial diversity (OTU count) in ME/CFS patients compared to healthy controls (p=0.045)
46% of detected bacterial genera were found exclusively in ME/CFS patients
ME/CFS patients showed higher relative abundance of the 10 most common bacterial types compared to controls
Three specific bacterial variants (ASV 191, 44, 75) were significantly more abundant in healthy controls than ME/CFS patients
Machine learning model achieved 93.5% accuracy (AUC=0.935) in distinguishing ME/CFS from healthy microbiota profiles
Inferred Conclusions
Gut microbiota composition differs significantly between ME/CFS patients and healthy controls, suggesting potential biological involvement in disease pathogenesis
Microbiota differences may be quantifiable and measurable enough to potentially support diagnostic approaches
Future research should investigate the functional consequences of these microbial differences and test whether therapies targeting the microbiome could benefit ME/CFS patients
Remaining Questions
Do these microbiota differences cause ME/CFS symptoms, result from them, or both? Do these findings apply to diverse geographic and demographic populations, or only the Polish cohort studied?
What This Study Does Not Prove
This study does not prove that gut bacteria changes cause ME/CFS—the differences observed could be consequences of the illness rather than causes. The study also does not establish whether these microbiota differences are clinically relevant, treatable, or present in all ME/CFS populations, as only a small group was studied. Correlation between microbial patterns and clinical symptoms was not examined.