Parkinson's disease might actually start in your gut long before it ever reaches your brain.
April 15, 2026
Original Paper
Myeloid-Driven Inflammation in Prodromal Parkinson's Disease
bioRxiv · 2025.05.16.654530
The Takeaway
For a long time, we viewed Parkinson’s strictly as a brain-first disorder, but scientists just found a smoking gun in the gut. They discovered that immune cells in the spinal fluid of people in the earliest stages of the disease are carbon copies of cells found in the digestive tract. This provides massive empirical weight to the 'gut-brain axis' theory, suggesting the disease begins as an inflammatory gut disorder. It means that what we call a brain disease might actually be a traveling immune response. If we can catch and treat this inflammation in the gut, we might be able to stop the brain damage before it even starts. This completely changes our strategy for early diagnosis and prevention.
From the abstract
We hypothesized that prodromal Parkinson's Disease (PD), characterized by REM Sleep Behavior Disorder and hyposmia, is an inflammatory disorder initiated in the gut that evolves into a neurodegenerative process manifest as classical PD. To test this hypothesis, we performed single-cell RNAseq analysis of cerebrospinal fluid (CSF) and blood from 118 individuals, comparing healthy subjects with prodromal PD and manifest PD to patients with the central nervous system (CNS) autoimmune disease, multi