Provotellaceae is a common bacteria family in the colon related to mucin synthesis in the mucosal layer of the gut and production of health-promoting neuroactive short chain fatty acids through fermentation of soluble fiber51, and Prevotella-derived hydrogen sulfide52 is thought to play a role in PD-related GI symptoms such as constipation and neuroprotection. Here, MUC5AC is linked to Parkinson disease.