Effects of Fecal Microbiota Transplantation on Inflammatory Markers in Parkinson’s Disease: Exploratory Results from the EFFACE-PD Study

Inflammation and gut dysbiosis are increasingly recognized as important contributors to the pathophysiology of Parkinson’s disease (PD). Fecal microbiota transplantation (FMT) has emerged as a potential therapeutic strategy aimed at restoring gut microbial balance and modulating inflammatory pathways. The aim of the study was to evaluate the effect of single fecal microbiota transplantation on systemic and gut-related inflammatory biomarkers in patients with PD. This exploratory analysis was conducted as part of the randomized, double-blind, placebo-controlled EFFACE-PD study. Fifty-nine participants with PD were randomized to receive either donor-derived FMT or placebo. Serum levels of IL-18 and calprotectin were measured using ELISA before intervention and 3 months after the procedure. Ferritin, leukocyte count, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) were assessed at baseline and after twelve months. No statistically significant between-group differences in changes in inflammatory biomarker concentrations were observed. Broader inflammatory markers, including ferritin and leukocyte parameters, also did not differ significantly between groups. We conclude that single FMT did not induce significant changes in systemic inflammatory biomarkers in this exploratory cohort of PD patients. Larger studies with standardized inflammatory assessments are needed to clarify the immunomodulatory effects of FMT in PD.