Microbial Diversity in Drug Naïve Parkinson’s Disease Patients

Parkinson’s disease is a neurological disorder characterized by rigidity, bradykinesia and tremor. Several genetic and environmental causes of Parkinson’s disease are known, and there is emerging evidence of the possible contribution of the gut microbiome to the disease onset, severity, and response to therapy. While previous research has shown several differences in the microbiome of Parkinson’s disease patients under therapy, few prospective studies have included drug naïve patients. In order to evaluate the gut microbiome composition prior to therapy initiation, we collected and performed 16S rRNA gene sequencing of the stool samples from 49 drug naïve Parkinson’s disease patients and compared them to 34 diet and lifestyle-matched controls from the Croatian population (GiOPARK Project). While no significant alpha diversity difference was observed between the patients and controls, the differential relative abundance analysis showed an increase in Bacteroides fluxus, B. interstinalis, B. eggerthii, and Dielma fastidiosa in the drug naïve Parkinson’s disease patients compared to controls, while Alistipes, Barnesiella nd Dialister spp. were decreased in patients compared to controls. Insight into the gut microbiome of Parkinson’s disease patients prior to therapy implementation represents a valuable baseline dataset for further studies.