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Parkinson Disease (PD)GBPDCNCT07567794

GBPDC: Gut-Brain in PD Consortium Master Protocol

An observational study of Parkinson Disease (PD) and PARKINSON DISEASE (Disorder), run by Duke University at 7 sites in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The purpose of this research study is to identify the role that the gut-brain axis, the group of nerves that connect the brain and gut, plays in Parkinson's disease (PD). The National Institute of Diabetes and Digestive and Kidney Diseases is sponsoring this research study. Read more about this study

Who is it for?
Ages 21 to 80 yearsHealthy volunteers can take part
How many people
250 participants
Where
7 sitesUnited States
Study dates
3 Jul 2026to 31 Dec 2028
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 21 to 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Patients at the NIDDK designated Gastroenterology Neurology Research Centers

Who may be able to join

  • 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
  • Willingness and ability to comply with scheduled visits, laboratory tests, and other study procedures. Because longitudinal participation is important to the scientific goals of the program, a "best estimate" of interest, commitment, and geographic feasibility for three years will be documented by the enrolling investigator after interview with the potential enrollee
  • Aged ≥21 years old and ≤80 years old
  • No known or diagnosed neurodegenerative disease
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  • Willingness and ability to comply with scheduled visits, laboratory tests, and other study procedures
  • Resides within the same household as person with PD
  • Aged ≥21 years old and ≤80 years old
  • Prodromal characteristics are defined by the MDS Research Criteria for PD and include either polysomnography (PSG)-confirmed rapid eye movement sleep behavior disorder (RBD) or possible RBD (questionnaire-based), with hyposmia as defined by the University of Pennsylvania Smell Identification Test (UPSIT) ≤ 15th percentile.

Who cannot join

  • Diagnosis of secondary or atypical parkinsonism
  • Laboratory Values:
  • Hemoglobin (Hgb) <10
  • Platelets <70,000
  • Alanine Transaminase (ALT) or Aspartate Aminotransferase (AST) > 2 1/2 times upper limit of normal (ULN)
  • 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)
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  • Significantly above the normal range for PT/INR/PTT
  • Currently taking anticoagulants that are deemed exclusionary by the investigator for risk of bleeding with sigmoidoscopy procedure
  • Clinically significant cognitive impairment with a Montreal Cognitive Assessment (MOCA) score <22
  • 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 nervous system including, but not limited to, syphilis, present hypothyroidism, present or unaddressed/treated vitamin B12 deficiency, or other screening laboratory abnormalities
  • Suicidality, defined as active suicidal thoughts or ideation within 6 months before Screening or at Baseline, defined as answering yes to items 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS), or history of suicide attempt in previous 2 years, or, in the Investigator's opinion, at serious risk of suicide
  • Has cancer or has had a malignant tumor within the past 5 years. (Participants with stable untreated prostate cancer or treated/removed cutaneous carcinomas are not excluded.)
  • Any medical condition or systemic disease that, in the Investigator's opinion, may either put the participant at risk because of participation in the study, influence the results or proposed analyses, or impair the participant's ability to fully participate in the study
  • Body mass index (BMI) >35 kg/m2 or body weight <50 kg
  • Participant is currently pregnant, breastfeeding, and/or lactating
  • History of alcohol or substance abuse or dependence within the past 2 years (DSM IV criteria)
  • History of Covid 19 (SARS-CoV-2) infection within 6 weeks prior to screening.
  • Participants with unresolved symptoms of Covid 19 infection or ongoing cognitive or other deficits attributable to post-Covid 19 that may affect participant safety or interfere with cognitive assessments based on the Investigator's clinical judgment
  • Either ongoing or current participation in another clinical trial with an investigational agent and have taken at least one dose of study medication, unless unblinded on placebo, within 4 weeks prior to the start of screening, or five half-lives of the investigational drug, whichever is greater. The end of a previous investigational trial is the date the last dose of an investigational agent was taken. Participation in other research studies (e.g., observational studies) may be acceptable throughout this study.
  • History of GI surgery. (However, patients with appendicectomy, hemorrhoid surgery, and cholecystectomy will be eligible to participate).
  • Regular use of medication that impacts the intestinal barrier (e.g., NSAID more than 3 times weekly)
  • Has a history of Crohn's disease, ulcerative colitis, and/or other types of colitis (microscopic, lymphocytic, or collagenous colitis). Confirmed diagnosis of inflammatory bowel disease (IBD) and/or, active or uncontrolled IBD symptoms such as diarrhea, bleeding, or severe stomach pain. Treatment for IBD in the past 6 months with medicines such as steroids, biologics, or strong immune-suppressing drugs. Surgery to remove part of the bowel due to IBD. Other long-term gut diseases that cause inflammation, such as celiac disease.

Trial locations and contacts

7 sites in 1 country. Contact the study team or a site near you to ask about taking part.

7 sites in 1 country

United States7 sites, 7 recruiting
  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

    Anna Borodianski, 617-724-0480, GIMotilityResearch@MGH.HARVARD.EDU

    Aleksander Videnovic, MD

    Recruiting
  • Medical University of South Carolina

    Charleston, South Carolina, 29425

    Stephanie N Slan, MBA, ACRP-CP, slans@musc.edu

    Not yet recruiting
  • Rush University

    Chicago, Illinois, 60612

    Michelle Villanueva, MS, 312-942-8927, michelle_villanueva@rush.edu

    Ali Keshavarzian, MD

    Recruiting
  • University of Chicago

    Chicago, Illinois, 60637

    Hanna Lancerio, 773-633-8412, hlancerio@bsd.uchicago.edu

    Tao Xie, MD, PhD

    Not yet recruiting
  • Columbia University

    New York, New York, 10027

    Katharine Godfrey, kb3217@cumc.columbia.edu

    Braden Kuo, MD

    Not yet recruiting
  • Mayo Clinic

    Rochester, Minnesota, 55905

    Kelly Feuerhak, BSN, RN, CCRP, 507-255-6802, rstgistudy@mayo.edu

    Adil Bharucha, MBBS, MD

    Recruiting
  • Stanford University

    Stanford, California, 94305

    Marian Shahid-Besanti, MSc, 650-723-0060, gutbrainresearch@stanford.edu

    Kathleen L Poston, MD, MS

    Recruiting

Other trials in United States

About this study

Official title: Consortium for Gut-Brain Communication in Parkinson's Disease Master Protocol

The purpose of this research study is to identify the role that the gut-brain axis, the group of nerves that connect the brain and gut, plays in Parkinson's disease (PD). The National Institute of Diabetes and Digestive and Kidney Diseases is sponsoring this research study.

During this study, specific groups of participants, also known as "cohorts", will be identified based on the severity of their PD. There will also be a cohort enrolling participants who do not have Parkinson's and a cohort enrolling participants that are at risk for developing PD. Each of these cohorts will be compared to the others to assess the differences in the gut-brain connection.

Read more

Participants in this study will:

  • meet with a medical provider
  • answer questionnaires
  • give samples of blood, stool, and saliva
  • have X-rays taken while swallowing different foods (swallowing study)
  • have X-rays taken to see how long it takes markers to move through their colon (colon transit study)
  • have a flexible sigmoidoscopy, where a doctor looks inside the lower part of the colon and takes small tissue samples (biopsies) from the mucosa (lining)
  • have samples taken of their skin
  • have an anorectal manometry and a balloon expulsion test, where a small tube and balloon are placed in the rectum to measure muscle function.

Participation in the study will last up to 24 months (2 years).

Read the detailed description

The objectives of the master protocol are to establish a common platform that: (1) assures the collection, integration, and analysis of a set of uniformly collected data across all participating centers, and (2) follows the objective of the Gut-Brain Parkinson's Disease Consortium (GBPDC) with the goal "to enhance our understanding of the temporal onset of GI symptoms in PD and changes in gut-brain communication that can be used to leverage the potential role of the GI tract in the pathogenesis and progression of PD and to improve patient diagnosis, care, and outcomes."

Primary Objective

  1. To collect prospective cross-sectional and longitudinal participant biospecimens with temporally coordinated evaluations of GI and neurological symptoms and functions to better characterize the phenotype of people with PD versus those without.

Secondary Objectives

  1. To elucidate the biological processes and pathways relevant to the role of the GI tract in the pathogenesis and progression of PD.
  2. To characterize GI symptoms, pathology, and gut-brain communication in PD to detect early and longitudinal changes in gut function and activity that correspond to the development or progression of PD.

Exploratory Objectives

  1. To identify possible novel gut-based biomarkers (functional, molecular, etc.), diagnostic tools, and therapeutic targets.
  2. To investigate the impact of neuroimmune interactions and other pathways in the GI tract on gut-brain communication and PD risk.

In conjunction with clinical, social, and environmental characterization, biospecimen collection within the GBPDC master protocol will provide the opportunity to probe and characterize the pathophysiologic underpinnings of the gut-brain axis in PD, refine existing biomarker testing for PD, and identify new biomarkers that could allow early detection of PD or new targets for treatment.

Duke University will serve as the biorepository for the GBPDC. Participants and study site personnel will collect, process, and ship biospecimens according to the GBPDC Biorepository Manual of Procedures using standard kits assembled specifically for the GBPDC master protocol. Biospecimens will be shipped from the study sites to the GBPDC central biorepository at Duke University for accessioning, storage, tracking, and subsequent distribution for use in approved future research. Throughout the conduct of the master protocol, a portion of the biospecimens received by the GBPDC central biorepository will be transferred to the NIDDK biorepository for approved research use. Any biospecimen aliquots remaining at the GBPDC central biorepository at the termination of the GBPDC program will be transferred to the NIDDK biorepository.

Statistical Design This is a prospective, observational, longitudinal cohort study designed to characterize gut-brain communication in Parkinson's Disease. The study employs a longitudinal design, including cross-sectional analyses of baseline data, to evaluate gastrointestinal and neurological functions in participants with PD compared to household controls and a prodromal cohort, as well as comparisons among PD severity subgroups.

Study Design Features:

  • Multi-center observational study across 5 GNRCs
  • Three participant cohorts: people with PD, people with prodromal features of PD, and household controls. The PD cohort will be further classified as mild, moderate, or severe PD.
  • Longitudinal design with assessments at baseline, 6, 12, 18, and 24 months
  • Comprehensive biospecimen collection coordinated with clinical assessments
  • Household control design where controls are matched to people with PD when available
Keywords
gut brain, Parkinson's disease, Prodromal Parkinson's disease, healthy control
Medical subject headings
Parkinson Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07567794
Study groupRoleWhat they receive
Household ControlsAge-similar household controls. Household control design where controls are matched to people with PD when available.
People with Parkinson's diseaseThe Parkinson's Disease (PD) cohort will be further classified as mild, moderate, or severe PD as classified by Hoehn and Yahr scale.
Prodromal Parkinson's diseasePeople with Parkinson's Disease prodromal features. Prodromal characteristics are defined by the MDS Research Criteria for PD and include either polysomnography (PSG)-confirmed rapid eye movement sleep behavior disorder (RBD) or possible RBD (questionnaire-based), with hyposmia as defined by the University of Pennsylvania Smell Identification Test (UPSIT) ≤ 15th percentile.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. GI influences on PD

    Trait and State cross-sectional evaluation of GI influences on PD

    Measured: enrollment to end of observation at 24 months

  2. Co-associations components of the GBA

    Cross-sectional co-associations components of the GBA

    Measured: enrollment to end of observation at 24 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 May 2026
  2. Study start3 Jul 2026
  3. Primary completion31 Dec 2028 (estimated)
  4. Study completion31 Dec 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
250 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07567794
Sponsor's protocol ID
Pro00115811
Other IDs
5U24DK140918-02, 5U01DK140933-02, 5U01DK140923-02, 5U01DK140921-02, 5U01DK140936-02, 5U01DK140939-02
Acronym
GBPDC
Status last verified
Jul 2026
First submitted
29 Apr 2026
Last updated
25 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: All IPD related to the GBPDC will be shared via requests submitted through the NIDDK Central Repository.

Questions about this trial

What is this clinical trial studying?

An observational study of Parkinson Disease (PD) and PARKINSON DISEASE (Disorder), run by Duke University at 7 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

GI influences on PD (time frame: enrollment to end of observation at 24 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Sep 2026; AzTrials last refreshed its copy on 26 Oct 2026.

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