Parkinson's disease: Are gut microbes involved?

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by motor and gastrointestinal (GI) deficits. Despite its prevalence, the pathophysiology of PD is not well understood. Recent studies highlight the role of gut microbiota in neurological disorders. In this review, we summarize the potential role of gut microbiota in the pathophysiology of PD. We first describe how gut microbiota can be influenced by factors predisposing individuals to PD, such as environmental toxins, aging, and host genetics. We then highlight the effect of gut microbiota on mechanisms implicated in the pathophysiology of PD, including disrupted microbiota gut brain axis (GBA), barrier dysfunction, and immune dysfunction. It is too early to connect the dots between gut microbiota and PD to establish causation, and experiments focused on investigating interrelationship between gut microbiota and associated metabolites on GBA, barrier dysfunction, and immune activation will be crucial to fill in the gaps.