Effects of Resistant Starch on Symptoms, Fecal Markers and Gut Microbiota in Parkinson′s Disease — The RESISTA-PD Trial

The composition of the gut microbiome is linked to multiple diseases, including Parkinson′s disease (PD). Bacteria producing short-chain fatty acids (SCFAs) and fecal SCFA concentrations are reduced in PD. SCFAs exert various beneficial functions in humans. In the interventional, monocentric, open-label clinical trial RESISTA-PD (NCT02784145) we aimed at altering fecal SCFAs by an 8-week prebiotic intervention with resistant starch (RS). We enrolled 87 subjects in three study-arms: 32 PD patients receiving RS (PD + RS), 30 control subjects receiving RS, and 25 PD patients receiving solely dietary instructions. We performed paired-end 100 base pair length metagenomic sequencing of fecal samples using the BGISEQ platform at an average of 9.9 GB. RS was well-tolerated. In PD + RS, fecal butyrate concentrations increased significantly and fecal calprotectin concentrations dropped significantly after 8 weeks of RS. Clinically, we observed a reduction in non-motor symptoms load in PD + RS. The reference-based analysis of metagenomes highlighted stable alpha-diversity and beta-diversity across the three groups, including bacteria producing SCFAs. Reference-free analysis suggested punctual, yet pronounced differences in the metagenomic signature in PD + RS. RESISTA-PD highlights that a prebiotic treatment with RS is safe and well-tolerated in PD. The stable alpha-diversity and beta-diversity alongside altered fecal butyrate and calprotectin concentrations calls for long-term studies, also investigating whether RS is able to modify the clinical course of PD.