"A diet that supports a healthy gut microbiome may help with Parkinson's disease (PD) by improving symptoms and potentially slowing disease progression:

Eat more fiber
Fiber-rich foods like jicama, kiwi, spinach, artichokes, and asparagus can help improve gut health.

Eat a Mediterranean-style diet
This whole-food based diet may lower the risk of developing PD and improve heart and cognitive health.

Eat healthy fats
Healthy fats like extra virgin olive oil, nuts, and seeds may ease PD symptoms.

Eat more fruits and vegetables
A Harvard study found that people who ate a lot of fruits, vegetables, beans, and whole grains had a lower risk of developing PD.

Eat lean protein
People with PD may burn more calories even at rest, so they may need to eat more calories.

Some research suggests that diet may play a role in preventing PD. People with PD may have changes in gut bacteria that can contribute to symptoms like constipation and inflammation. A healthier diet can increase the amount of anti-inflammatory bacteria in the gut and decrease the amount of pro-inflammatory bacteria"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC69....

Diet in Parkinson's Disease: Critical Role for the Microbiome

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6915094/