Parkinson's Disease Biomarkers in Nerve Cells in the Gut

Inclusion Criteria:

* Age 45-75 years old
* Parkinson's Disease defined by the modified UK Parkinson's Disease Society Brain Bank criteria, at risk for the development of Parkinson's disease including REM sleep behavior disorder and/or at least one first degree relative with PD or related disorder, and diseases related to Parkinson's disease including the synucleinopathies Lewy Body Dementia and Multiple System Atrophy.
* Baseline Hoehn \& Yahr score 1-4
* No contraindications to undergoing screening colonoscopy
* Able to give informed consent for study participation

Exclusion Criteria:

* Clinical features suggestive of a neurodegenerative diagnosis other than synucleinopathy.
* Diagnosis of primary mitochondrial disorder, epilepsy, stroke, multiple sclerosis or other neurodegenerative diseases such as Alzheimer's disease, Progressive Supranuclear Palsy (PSP), and Corticobasal syndrome.
* Significant concomitant medical disease limiting life expectancy to less than 24 months from study inclusion, or significant and serious concomitant medical disease that is poorly controlled
* Signs of active malignant disease or other clinically relevant abnormality on chest x-ray
* Active or untreated gastrointestinal disease
* Inability to temporarily stop anti-platelet agents or other anti-coagulants without significant risk
* Known substance abuse (recent history of abuse of alcohol or other drugs such as barbiturates, cannabinoids and amphetamines) within last 5 years
* Contraindication to colonoscopy or associated anesthesia
* Pregnancy
* In the opinion of the investigator, any other condition regarded as making subject unsuitable for the study