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NCT07418658Not yet recruiting

Untreated Parkinson's Disease Work-up Assessing Resident Microbiota and Duodenal Barrier Function

Multimodal Characterization of Gastrointestinal Structure, Function, and Microbiome in Drug-Naïve Parkinson's Disease

Source: ClinicalTrials.gov · Last updated 18 Feb 2026

Brief summary (registry, in English)

The UPWARD study is a prospective hypothesis-generating study in individuals with untreated Parkinson's disease (PD) and age-matched healthy controls (HCs). The objective of the study is to characterise disease-driven gastrointestinal (GI) changes that occur prior to initiation of treatment. The main questions this study aims to answer are: 1. Are there changes in duodenal permeability in people with untreated PD? 2. Are there changes in the gut microbiome in people with untreated PD? 3. Are these gut changes linked to prodromal features, or movement and non-movement symptoms of PD? The study consists of a screening visit, followed by a six-day home phase and one subsequent study visit at UZ Leuven. During the home phase, participants collect a stool sample, ingest radiopaque markers to assess gut transit time, and complete questionnaires. During the study visit, participants undergo an abdominal X-ray, a clinical assessment, and blood sampling. An upper GI endoscopy with duodenal biopsies is offered as an optional component of the study. This study does not test a therapeutic intervention. Examinations as part of the study are not standard clinical care. The findings are expected to improve understanding of early GI involvement in PD and to inform future mechanistic and clinical research.

Status (registry)
Not yet recruiting
Study type
Observational
Enrollment
100 (estimated)
First submitted
26 Jan 2026
Start date
1 Feb 2026
Primary completion date
28 Feb 2029
Lead sponsor
Universitaire Ziekenhuizen KU Leuven
NCT number
NCT07418658

What you commit to

  • Study type: Observational
  • Planned participants: 100
  • From 1 Feb 2026 to the primary completion date, 28 Feb 2029
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Criteria the registry did not label

  • \* Inclusion criteria:
  • Patients eligible for inclusion in this study must meet all of the following criteria:
  • Diagnosis of Parkinson's Disease by a neurologist according to the Movement Disorder Society Clinical Diagnostic Criteria for PD
  • Signed informed consent form
  • Aged 18-75 years old
  • Able to understand the study and questionnaires, and comply with study requirements
    • Controls eligible for inclusion in this study must meet all of the following criteria:
  • Aged 40-75 years old
  • Signed informed consent form
  • Able to understand the study and questionnaires, and comply with study requirements
    • Exclusion criteria:
    • Participants eligible for this study must not meet any of the following criteria:
    • Patients and controls:
  • Gastrointestinal: diagnosis of organic gastrointestinal diseases potentially affecting the assessments during the study (e.g. inflammatory bowel disease (IBD), celiac disease, eosinophilic diseases of the gastro-intestinal tract, gastro-intestinal cancer, diverticulitis in the last 6 months, GI infection in the last 3 months, …).
  • Surgery: major abdominal surgery (including, but not limited to: cholecystectomy, colectomy, hiatal hernia repair, …) except for uncomplicated appendectomy, splenectomy and inguinal hernia repair.
  • Medication use:
    • Any previous exposure to medication used in the treatment of motor symptoms of Parkinson's disease (levodopa, dopamine agonists, MAO-B inhibitors, COMT-inhibitors, NMDA-receptor antagonists, anticholinergics)
    • Antibiotics use in the last 3 months.
    • Use of PPI in the last month.
    • Use of NSAID in the last month.
    • Use of anticoagulation4 (including vitamin K antagonists (VKA), direct oral anticoagulants (DOAC) or low-molecular weight heparins (LMWH)) or dual antiplatelet therapy4 (DUAPT; Acetylsalicilic acid (Asaflow®) + P2Y12-inhibitor (Clopidogrel®)).
  • Pregnancy and breastfeeding.
  • Other: Cancer and/or adjuvant treatment within the last 6 months
  • Exposures:
    • Food intoxication in the last 3 months.
    • Consumptom of more than 2 standard units of alcohol per day.
    • Patients (additional criteria)
    • 1\. Neurological: any major neurological disorder other than Parkinson's disease.
    • Controls (additional criteria)
  • Neurological:
    • A diagnosis of Parkinson's disease or any other major neurological disorder other than Parkinson's disease.
    • Clinical signs of parkinsonism.
    • First degree relative(s) with Parkinson's disease.
  • Gastrointestinal: subjects fulfilling a clinical diagnosis of either Functional dyspepsia, Functional constipation, or Irritable bowel syndrome based on the ROME-IV diagnostic criteria.

Age in the registry: 18 years to 75 years · Sex: All · Accepts healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Pick your city on the disease page to sort them by distance.

SiteCityCountrySite status
UZ Leuven
Coordinator of this site? Confirm its status		LeuvenBelgiumUnknown status

This page is information, not medical advice. Discuss any trial with your doctor.