NCT05347407 · Weill Medical College of Cornell University
Parkinson's Disease Biomarkers in Nerve Cells in the Gut
(PD-ENS)
What this study is about
Parkinson's disease affects all the nerve cells in the body, including the ones in the gut. The gut contains its own nervous system, the enteric nervous system, and can be thought of as a "second brain". This second brain can reflect what is going on in the actual brain.
View original scientific description
Parkinson's disease affects all the nerve cells in the body, including the ones in the gut. The gut contains its own nervous system, the enteric nervous system, and can be thought of as a "second brain". This second brain can reflect what is going on in the actual brain. This study is being done to look for biomarkers, or early indicators of developing Parkinson's disease, in the microbiome and in the gut tissue taken during routine screening colonoscopy. People aged 45 and over who are due for their routine screening colonoscopy are eligible to participate.
Interventions
PROCEDURE
Colonoscopy
Patients will be provided with a kit and be asked to bring a stool sample to their colonoscopy appointment. Mucosal biopsies will be collected with standard forceps during colonoscopy. If the physician determines that the patient will need colonoscopy with biopsy as part of their routine clinical care, they will take 6-8 additional biopsies for use in the research study. If the physician determines that the patient will need colonoscopy without biopsy as part of their routine clinical care, they will take 6-8 biopsies for use in the research study only. The collection of additional biopsies will add an estimated two minutes to the whole procedure.
Primary outcome measures
Biochemical changes in enteric nervous system
Time frame: A single timepoint will be evaluated on biopsy samples taken from subjects during routine screening colonoscopy.
The primary objective of the study is to assess the abundance and subcellular distribution of alpha-synuclein and other Parkinson's disease-related proteins in the enteric nervous system of PD patients and healthy controls.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- In the opinion of the investigator, any other condition regarded as making subject unsuitable for the study
Where
- New York, New York
Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 22, 2026 · Source of record for eligibility and locations