A systematic review of enteric dysbiosis in chronic fatigue syndrome/myalgic encephalomyelitis.
Du Preez, S, Corbitt, M, Cabanas, H et al. · Systematic reviews · 2018 · DOI
Quick Summary
Researchers reviewed seven studies looking at whether gut bacteria differences might cause ME/CFS symptoms. While all studies found some differences in gut bacteria between ME/CFS patients and healthy people, the findings were inconsistent and often not statistically significant. Currently, there isn't enough reliable evidence to say that abnormal gut bacteria are a major cause of ME/CFS.
Why It Matters
Understanding potential gut microbiome changes in ME/CFS could lead to new diagnostic tools or targeted treatments like probiotics. This systematic review critically evaluates current evidence and identifies the need for higher-quality research using consistent diagnostic criteria and methods, which could ultimately improve how we understand and treat ME/CFS.
Observed Findings
All seven included studies reported differences in microbiome composition between CFS/ME patients and healthy controls.
Only three of the seven studies found these differences to be statistically significant.
Microbiome findings across all studies were inconsistent and varied in methodology and outcomes.
Study quality varied widely, with ratings ranging from poor (<54%) to good (94-100%).
The review identified significant confounding variables and lack of standardized diagnostic criteria across studies.
Inferred Conclusions
Current evidence is insufficient to establish enteric dysbiosis as a significant mechanism in CFS/ME pathogenesis.
Inconsistent findings highlight the need for more rigorous, methodologically standardized research in this area.
Future studies should use consistent CFS/ME diagnostic criteria and control for variables known to influence microbiome composition.
More severe cases of ME/CFS should be included in future microbiome research.
Remaining Questions
Do specific microbiome alterations correlate with particular ME/CFS symptom profiles or disease severity?
What This Study Does Not Prove
This review does not prove that gut dysbiosis causes ME/CFS symptoms—it only examines whether differences exist. The inconsistency across studies and methodological limitations mean we cannot yet determine whether microbiome changes are a primary cause, secondary effect, or clinically meaningful contributor to ME/CFS pathogenesis.