Diet-driven approach to ease constipation in people with Parkinson’s

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This interventional study tests whether a dietitian-guided nutrition program can help people with Parkinson’s disease who have functional constipation. Participants follow a tailored diet plan designed around dietary reference intakes for three months, with periodic dietitian follow-ups and assessments at baseline, mid-point, and end. The study compares this targeted intervention to general dietary guidance given after the study period to determine effects on bowel function, gut microbiota, dietary intake, and nutritional status. Eligible participants are adults with Parkinson’s disease on stable levodopa therapy and a Rome IV-confirmed constipation diagnosis, while several medical conditions and recent antibiotic or laxative use exclude participation.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Adults with a previous diagnosis of Parkinson's disease
* On a stable dose of levodopa for at least 3 months
* Diagnosis of Functional Constipation by the Rome IV protocol

Exclusion Criteria:

* Diagnosis of atypical or secondary parkinsonism
* Hoehn and Yahr stage greater than 2
* Presence of severe neurological or psychiatric disorders that impair the ability to participate in study procedures
* Previous diagnosis of dementia
* Presence of comorbidities such as active cancer, chronic obstructive pulmonary disease (COPD), heart failure, and/or chronic kidney disease
* History of gastrointestinal cancers, inflammatory bowel diseases, or surgeries involving the gastrointestinal tract
* Constipation secondary to clinical conditions such as hypothyroidism or diabetes mellitus
* Use of opioids
* Use of probiotics or antibiotics in the past 8 weeks
* Continuous use of laxatives in the past 8 weeks
* Presence of severe dysphagia according to the Functional Oral Intake Scale (FOIS)
* Individuals receiving enteral or parenteral nutrition
* Individuals under nutritional follow-up in the past 3 months

Where it's running

• Hospital de Clínicas de Porto Alegre (HCPA)
  Porto Alegre, Rio Grande do Sul, Brazil Recruiting

Study contacts

• Principal investigator: Maira Rozenfeld Olchik, PhD — Federal University of Rio Grande do Sul
• Study coordinator: Maira Rozenfeld Olchik, PhD
• Email: molchik@hcpa.edu.br
• Phone: +55 (51) 33083020

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.