February 15, 2026

@michaelokun

A new randomized fecal microbiota transplantation study just dropped in Parkinson’s disease. Spoiler alert: Disappointing motor effects, however some positive non-motor signals. What is fecal microbiota transplantation? Fecal microbiota transplantation or FMT means transferring processed stool from a healthy donor into the gut of another person in an effort to reshape gut bacteria. Figura and colleagues describe in a new paper in the Annals of Neurology a randomized, placebo controlled, double-blinded study testing whether a single colonoscopy delivered FMT could improve motor and non-motor symptoms in Parkinson’s disease over 12 months. Key Points: - The primary outcome was not met. A single donor derived FMT did not significantly improve MDS UPDRS III motor scores in the OFF state at 12 months when it was compared to placebo. - Early and sustained improvements were observed in several non-motor domains including MDS NMS total score at 12 months, as well as cognition, pain, sexual dysfunction and gastrointestinal symptoms when measured at selected timepoints. - The procedure was generally safe and well tolerated, and no serious adverse events were reported over the 12 month follow-up. My take: This is an important and rigorous study. It tells us that changing the gut microbiome once via colonoscopy is not a 'motor game changer' at least when followed over about a year. However, the consistent signals in non-motor symptoms should get our attention and reinforce the concept of a gut-brain-axis in Parkinson’s disease. Here are 5 points that resonated w/ me: 1- A single FMT did not slow motor progression in the OFF state, which should temper enthusiasm for dramatic disease modifying claims. 2- Non-motor symptoms including pain and cognitive domains showed meaningful improvements in some timepoints, which the authors argue may matter for daily life. 3- Quality of life signals on EQ 5D favored donor FMT at 12 months, suggesting possible broader impact beyond motor scores. 4- The study used auto FMT as placebo, which is a stronger control group. 5- Future? Repeated dosing, earlier stage or precision microbiome? #michaelokun #fixelinstitute #parkinson