E1 ReplicatedPreliminaryPEM unclearRCTPeer-reviewedMachine draft
Randomized, double-blinded, placebo-controlled pilot study: efficacy of faecal microbiota transplantation on chronic fatigue syndrome.
Salonen, Tapani, Jokinen, Elina, Satokari, Reetta et al. · Journal of translational medicine · 2023 · DOI
Quick Summary
Researchers tested whether transplanting gut bacteria from healthy donors into ME/CFS patients could reduce fatigue and improve quality of life. Eleven patients received either bacteria from a healthy donor or their own bacteria (a placebo control) via colonoscopy, and their symptoms were tracked for six months. The treatment was safe, but it did not improve fatigue, pain, or overall quality of life compared to placebo.
Why It Matters
Given evidence linking gut dysbiosis to neurological symptoms in other conditions, testing FMT in ME/CFS was a reasonable hypothesis. This negative, well-controlled result helps redirect research focus and prevents investment in ineffective interventions, while establishing the safety of FMT delivery in this population.
Observed Findings
- VAS fatigue severity scores showed minimal change in both groups over 6 months (donor FMT: 62.4→72.8; placebo: 76.0→69.5), with no significant between-group differences at any timepoint.
- MFIS total scores were comparable at baseline (FMT 59.6 vs placebo 61.0) and remained largely unchanged through 6 months with no significant between-group differences.
- 15D and EQ-5D-3L quality-of-life profiles showed no meaningful changes in either treatment group.
- No FMT-related adverse events were reported, establishing procedural safety in this population.
Inferred Conclusions
- FMT did not provide symptomatic or quality-of-life benefits over placebo in this ME/CFS cohort.
- FMT appears safe as delivered via colonoscopy in ME/CFS patients without reported adverse events.
- Microbiota-targeted intervention via single FMT dose may be insufficient to address ME/CFS pathophysiology, or dysbiosis may not be a primary driver of symptoms in these patients.
Remaining Questions
- Would repeated FMT doses or longer follow-up periods yield different outcomes?
- Do specific microbiota profiles or patient subgroups respond differently to FMT?
- Are alternative microbiota-targeted interventions (prebiotics, targeted probiotics) more effective than FMT?
What This Study Does Not Prove
This small pilot study does not rule out microbiota dysfunction in ME/CFS pathogenesis—only that FMT as delivered here did not improve symptoms. It does not establish whether donor selection, timing, dose, or delivery method were optimal, nor does it exclude dysbiosis-related mechanisms in a subset of patients. Negative results in a 11-person study cannot definitively exclude benefit in larger or more genetically or clinically stratified populations.
Tags
Symptom:Fatigue
Method Flag:Weak Case DefinitionSmall Sample
Metadata
- DOI
- 10.1186/s12967-023-04227-y
- PMID
- 37516837
- Review status
- Machine draft
- Evidence level
- Replicated human evidence from multiple independent studies
- Last updated
- 8 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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