Fecal microbiota transplantation in Parkinson's disease: a systematic review
In brief
Fecal transplant improves motor symptoms in four of six Parkinson trials
A review of 14 studies involving 369 Parkinson patients found fecal microbiota transplantation to be generally safe, with only mild, transient side effects. Four of six controlled trials reported modest short-term motor improvements, while non-motor benefits were inconsistent. Small, heterogeneous samples limit confidence, underscoring the need for larger, standardized trials.
- Journal
- Neurodegenerative disease management (Q2)
- Published
- 10 August 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Negin Eissazade, Hesam Mosavari, Shayan Eghdami, Mohammad Rohani, Seyed-Mohammad Fereshtehnejad, Tara Khoeini
- PMID
- 42574556
- DOI
- 10.1080/17582024.2026.2715585
Why clinicians should know about it
- Picked for Microbiology (medical) (top studies of the week, 16 August 2026): High-quality evidence in a top journal
Abstract
INTRODUCTION: Current Parkinson's disease (PD) treatments offer limited, temporary relief. Fecal microbiota transplantation (FMT) is a potential therapy, but its safety and efficacy remain unclear. METHODS: PubMed, Scopus, Cochrane Library, and Web of Science were searched on 20 July 2026. Eligible studies included adults with PD receiving FMT reporting motor and non-motor outcomes. Study quality was assessed using Joanna Briggs Institute checklists and Cochrane RoB 2. Due to heterogeneity, results were synthesized narratively. RESULTS: Fourteen studies (nine trials, three case series, two case reports; 369 participants) were included. FMT protocols varied in stool preparation, delivery route, regimen, and follow-up (3-12 months). Four of six trials reported modest, short-term motor improvements. Non-motor benefits, mainly gastrointestinal function, sleep, and mood, were inconsistent. Microbiota analyses showed partial or temporary restoration toward healthy profiles. FMT was generally safe, with mainly mild, transient adverse events. Risk of bias varied: two high, four some concerns, one low. CONCLUSIONS: FMT appears safe and may provide short-term improvements in select motor and gastrointestinal outcomes in PD. Evidence is limited by small samples, heterogeneity, and methodological weaknesses. Well-designed, adequately powered RCTs with standardized protocols are needed to determine its therapeutic and disease-modifying potential. REGISTRATION: PROSPERO (CRD42024508462).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.