Oral and intestinal dysbiosis in Parkinson's disease

Area of Science:

• Neuroscience
• Microbiology
• Gastroenterology

Background:

• Parkinson's disease (PD) research increasingly focuses on the gut microbiota due to suspected peripheral origins and environmental risk factors.
• The gut microbiota, comprising microorganisms in and on the host, is crucial for physiological functions and has been implicated in PD pathogenesis.

Purpose of the Study:

• To review the role of gut dysbiosis in Parkinson's disease.
• To explore how dysbiosis influences PD symptoms, pathophysiology, and treatment response.
• To discuss dysbiosis as a potential biomarker and therapeutic target for PD.

Main Methods:

• Literature review of studies investigating the gut microbiota in Parkinson's disease.
• Analysis of animal models demonstrating the link between dysbiosis and PD-like symptoms.
• Examination of metabolic and inflammatory changes associated with dysbiosis in PD.

Main Results:

• Repeatedly demonstrated dysbiosis in PD is associated with both motor and non-motor symptoms.
• Dysbiosis promotes PD symptoms in genetically susceptible individuals, indicating it's a risk factor, not a cause.
• Dysbiosis contributes to PD pathophysiology via increased intestinal permeability, inflammation, bacterial amyloid production, and reduced beneficial short-chain fatty acids.

Conclusions:

• Gut dysbiosis is a significant risk factor in Parkinson's disease, influencing disease progression and symptom severity.
• Dysbiosis negatively impacts the efficacy of dopaminergic treatments for PD.
• Modulating the gut microbiota through interventions like diet, probiotics, or fecal microbiota transplantation holds potential for managing PD.