Associations Between Gut Microbiota Composition and Impulse Control Disorders in Parkinson's Disease.

Impulse control disorders (ICDs) are a debilitating non-motor symptom of Parkinson's disease (PD), often associated with dopaminergic therapy. However, their occurrence in some patients but not others suggests additional biological mechanisms, including the gut microbiome. In this study, we analyzed 191 PD patients (14 with ICDs, 177 without) using 16S rRNA gene sequencing to explore the association between gut microbiota and ICDs. No significant differences were observed in alpha or beta diversity between groups, but several bacterial taxa showed differential abundances. Notably, Methanobrevibacter and Intestinimonas butyriciproducens were enriched in ICD patients. Functional pathway analysis revealed differences in metabolic pathways, including enrichment of xenobiotic degradation and nicotinate metabolism in the ICD group. These findings suggest that specific gut microbial taxa and their associated metabolic functions may contribute to ICDs in PD, highlighting a potential non-dopaminergic mechanism and opening new avenues for microbiome-targeted intervention.