Objective: To evaluate the efficacy and safety of Fecal Microbiota Transplantation (FMT) in patients with Parkinson’s disease (PD).
Background: FMT is a novel therapy for PD due to its potential to modulate gut-brain axis interactions. Evidence suggests gut dysbiosis may contribute to PD symptom progression [1]. This systematic review and meta-analysis assess the efficacy and safety of FMT in alleviating motor and non-motor symptoms in PD patients.
Method: PubMed, EMBASE, and Cochrane Central databases were searched for randomized controlled trials (RCTs) comparing FMT with placebo. Efficacy and safety outcomes were analyzed using Review Manager 5.4, with mean differences (MDs) calculated using random-effects models.
Results: We analyzed four RCTs comprising 157 patients, 87 undergoing allogenic FMT and 70 receiving either placebo or autologous FMT [2-5]. Surprisingly, the Wexner Constipation Score showed significant improvement in the Placebo group (MD 1.56, 95% CI [1.00, 2.12]; p < 0.00001). However, no significant improvement was observed in the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) (MD -1.83, 95% CI [-7.09, 3.44], p = 0.50), which was the primary outcome. Similarly, secondary outcomes, including the Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) score, levodopa-equivalent daily dose (LEDD) (mg), Non-Motor Symptoms Scale (NMSS), Montreal Cognitive Assessment (MoCA), and Parkinson Disease Questionnaire Summary Index (PDQ-39 SI) score, showed no significant improvement. A sensitivity analysis was conducted due to high heterogeneity, revealing no significant changes in the primary outcome. However, the NMSS score (before: MD 1.17, 95% CI [-0.03, 2.36], p = 0.06) showed improvement following the sensitivity analysis (after: ). Reported adverse effects in the FMT group included stomach ache, nausea, gastrointestinal dysfunction, and worsening anxiety.
Conclusion: The pooled results of our meta-analysis were unfavorable for the FMT therapy. However, individual results of the RCTs were promising, highlighting the potential of this therapy. There is a dire need for robustly designed RCTs with larger sample sizes.
Fig02. Forest Plots of FMT vs. Placebo.
Fig 03. Forest Plot of LEDD (mg)
Table 1. Characteristics of the Included Studies
Fig 04. Forest Plots after Sensitivity Analysis
Figure 01. PRISMA flow diagram
References: 1. Sun MF, Zhu YL, Zhou ZL, et al. Neuroprotective effects of fecal microbiota transplantation on MPTP-induced Parkinson’s disease mice: Gut microbiota, glial reaction and TLR4/TNF-α signaling pathway. Brain Behav Immun. 2018;70:48-60. doi:10.1016/j.bbi.2018.02.005
2. Scheperjans F, Levo R, Bosch B, et al. Fecal Microbiota Transplantation for Treatment of Parkinson Disease: A Randomized Clinical Trial. JAMA Neurol. 2024;81(9):925-938. doi:10.1001/jamaneurol.2024.2305
3. DuPont HL, Suescun J, Jiang ZD, et al. Fecal microbiota transplantation in Parkinson’s disease-A randomized repeat-dose, placebo-controlled clinical pilot study. Front Neurol. 2023;14:1104759. Published 2023 Mar 2. doi:10.3389/fneur.2023.1104759
4. Bruggeman A, Vandendriessche C, Hamerlinck H, et al. Safety and efficacy of faecal microbiota transplantation in patients with mild to moderate Parkinson’s disease (GUT-PARFECT): a double-blind, placebo-controlled, randomised, phase 2 trial. EClinicalMedicine. 2024;71:102563. Published 2024 Mar 27. doi:10.1016/j.eclinm.2024.102563
5. Cheng Y, Tan G, Zhu Q, et al. Efficacy of fecal microbiota transplantation in patients with Parkinson’s disease: clinical trial results from a randomized, placebo-controlled design. Gut Microbes. 2023;15(2):2284247. doi:10.1080/19490976.2023.2284247
To cite this abstract in AMA style:
A. Koppanatham, A. Bin Gulzar, M. Ammar Arshad, E. de Farias, V. Suresh, M. Tariq, R. Vasireddy, T. Varkey. Efficacy And Safety of Fecal Microbiota Transplant for Parkinson’s Disease: A Systematic Review And Meta-Analysis [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/efficacy-and-safety-of-fecal-microbiota-transplant-for-parkinsons-disease-a-systematic-review-and-meta-analysis/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/efficacy-and-safety-of-fecal-microbiota-transplant-for-parkinsons-disease-a-systematic-review-and-meta-analysis/