Research Progress of Microbiota-Gut-Brain Axis in Parkinson's Disease

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by misfolding of α-synuclein. Clinical manifestations include slowly developing resting tremor, muscle rigidity, bradykinesia and abnormal gait. The pathological mechanisms underlying PD are complex and yet to be fully elucidated. Clinical studies suggest that the onset of gastrointestinal symptoms may precede motor symptoms in PD patients. The microbiota-gut-brain axis plays a bidirectional communication role between the enteric nervous system and the central nervous system. This bidirectional communication between the brain and gut is influenced by the neural, immune and endocrine systems related to the gut microbiome. A growing body of evidence indicates a strong link between dysregulation of the gut microbiota and PD. In this review, we present recent progress in understanding the relationship between the microbiota-gut-brain axis and PD. We focus on the role of the gut microbiota, the unique changes observed in the microbiome of PD patients, and the impact of these changes on the progression of PD. Finally, we evaluate the role of current treatment strategies for PD, including probiotics, fecal microbial transplants, dietary modifications, and related drug therapies.