Probing Gut-Brain Communication in Parkinson's Disease

Inclusion Criteria: * Aged ≥21 years old and ≤80 years old * Clinical diagnosis of PD as defined by Movement Disorder Society (MDS) PD Criteria * Adequate visual, hearing, cognitive, and physical ability Exclusion Criteria: * Diagnosis of secondary or atypical parkinsonism * Laboratory Values: a: Hemoglobin (Hgb) \<10; b: Platelets \<70,000; c: Alanine Transaminase (ALT) or Aspartate Aminotransferase (AST) \> 2 1/2 times upper limit of normal (ULN); d: Moderate or severe renal disease with an estimated glomerular filtration rate (eGFR) \<60 mL/min/BSA \[body surface area\] calculated using the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation, or moderate or severe hepatic impairment (alkaline phosphatase \[ALP\] \>2.0 times the ULN and/or total bilirubin \>2.0 times the ULN); e: Significantly above the normal range for PT/INR/PTT. * Clinically significant cognitive impairment with a Montreal Cognitive Assessment (MOCA) score 35 kg/m2 or body weight * Clinical or laboratory findings consistent with another primary neurodegenerative disease or cognitive disorder other than PD, including but not limited to, frontotemporal lobar disease, Huntington's disease, progressive supranuclear palsy, multisystem atrophy, Creutzfeld-Jakob- Disease, Down's syndrome, cortico-basal degeneration, dementia with Lewy Bodies, Alzheimer's disease, amyotrophic lateral sclerosis, seizure disorder, stroke, or other infectious, metabolic, or systemic disease affecting the central…