Fecal transplantation in patients with Parkinson's disease

Is fecal microbiota transplantation (FMT) safe and does it improve symptoms in Parkinson disease (PD)?

In a new randomized clinical trial (JAMA Neurol. 2024;81(9):925-938) including 45 patients with PD, FMT was linked to mostly transient gastrointestinal adverse events without clinically meaningful improvements; in the placebo group, dopaminergic medication increased faster, and there was some clinical improvement.

While FMT induced stronger, donor dependent, microbiota changes, dysbiosis resolved more frequently after placebo.

Meaning FMT was safe but did not improve PD symptoms more than placebo; improvements and microbiome changes after placebo warrant further research on FMT and bowel cleansing in PD.