Nutritional Intervention for Constipation Symptoms in Patients With Parkinson's Disease

The goal of this clinical trial is to evaluate whether a dietitian-guided nutritional intervention can improve constipation symptoms in people with Parkinson's disease (PD). The main questions it aims to answer are: * Can a dietitian-guided nutritional intervention increase the number of weekly bowel movements in individuals with PD and functional constipation? * Can this intervention positively influence gut microbiota composition, dietary intake, and nutritional status? Researchers will compare the intervention group to a control group that will receive general dietary guidance only after the study period, to see if the intervention leads to improvements in bowel function and related health outcomes. Participants will: * Follow a diet plan developed by a dietitian, based on dietary reference intakes and tailored to the needs of individuals with PD and constipation * Participate in follow-up sessions with the dietitian for 3 months * Complete assessments at baseline, midpoint, and end of the intervention to evaluate bowel function, constipation symptoms, gut microbiota, nutritional status, and diet quality

NCT Number	NCT07213856
Lead Sponsor	Hospital de Clinicas de Porto Alegre
Conditions	Parkinsons Disease (PD), Constipation - Functional
Enrollment	54 participants
Start Date	2026-04-02
Primary Completion	2027-06 (estimated)
Study Completion	2029-08 (estimated)
Updated on ClinicalTrials.gov	2026-06-16