Seminar: Diet and the gut microbiome in Parkinson's disease

Abstract: Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide. While best known for its motor symptoms, people with PD also commonly exhibit gastrointestinal symptoms including differences in the types and abundances of their gut bacteria. Different types of bacteria have different nutritional requirements, and host diet can therefore strongly affect the gut microbiome. The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet is designed to optimize cognitive health and restricts foods common in Westernized populations such as fast, fried, or processed food. In a human PD cohort (n=298), the MIND diet correlated with lower inflammation, a later PD onset, and slightly slower disease progression. The gut bacteria in the people with PD ate fewer carbohydrates, favouring protein, and seemed to be weakly associated with worse disease outcomes. While the strongest correlation between the MIND diet and the gut was the reduction of pro-inflammatory bacteria, people with PD who had very strong gut differences had lower MIND scores and tended to have faster disease progression. Overall, this suggests that the gut bacterial changes may impact PD, and that the MIND diet may help to reduce the burden of PD through microbiome-dependent and independent mechanisms.