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.