Resistant starch improves Parkinson’s disease symptoms through restructuring of the gut microbiome and modulating inflammation
This randomized, controlled, long-term dietary intervention study examined whether adding resistant starch to the diet could improve gut health, inflammation, and symptoms in people with Parkinson’s disease. The study included 74 adults aged 40–85 with mild to moderate Parkinson’s disease. Participants were assigned to one of three groups: a standard diet, a resistant starch supplement added to a standard diet, or a high-fibre diet. A subset of the supplement group continued the intervention long term.
Researchers tracked changes in the gut microbiome using shotgun metagenomics, measured fecal metabolites such as short-chain fatty acids, analyzed inflammation-related proteins in blood, and assessed Parkinson’s symptoms and quality of life using established clinical scales.
The study found that resistant starch supplementation consistently shifted the gut microbiome in a beneficial direction. Participants showed increases in Faecalibacterium species and higher levels of short-chain fatty acids, especially acetate, alongside reductions in bacteria linked to inflammation and Parkinson’s disease. Over the long term, resistant starch intake was associated with meaningful improvements in motor symptoms, non-motor symptoms, and overall quality of life. These changes were accompanied by higher blood levels of APOA4 and HSPA5, proteins linked to anti-inflammatory and neuroprotective processes, as well as lower erythronic acid, suggesting improved mitochondrial function. Multi-omics analyses connected these biological changes directly to clinical improvement.
Together, these results suggest that resistant starch may help improve Parkinson’s disease symptoms by reshaping the gut microbiome, boosting beneficial microbial metabolites, and reducing inflammation. However, the study has limitations, including a small long-term sample size, lack of a long-term control group, and the absence of blinding or placebo control. Future studies should test these findings in larger, placebo-controlled trials and explore additional molecular mechanisms. Overall, the study supports the idea that targeted dietary fiber interventions can meaningfully influence the gut–brain axis in Parkinson’s disease.
