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

NCT07213856 | Not Yet Recruiting

• 1 other identifier: 2025-0374
• Study Type: interventional
• Target: 54
• Locations: 1 country
• Sites: 1

Brief Summary

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

Conditions

Parkinsons Disease (PD); Constipation - Functional

Keywords

Microbiota; Diet; Diet, Protein-Restricted; Diet Therapy; Diet, Healthy; Nutrition Therapy; Constipation; Non-Motor Symptoms; Nutritionists

Outcome Measures

Primary Outcomes (1)

• Change in weekly bowel movement frequency

  Mean change in the number of spontaneous bowel movements per week from baseline to 12 weeks, based on participant-reported bowel diaries.

  Baseline and 90 days

Secondary Outcomes (1)

• Change in relative abundance of gut microbial taxa

  Baseline and 90 days

Other Outcomes (1)

• Change in dietary intake

  Baseline, 45 days and 90 days

Study Arms (2)

Nutritional Intervention Group

EXPERIMENTAL

Participants will receive a tailored diet plan made by a registered dietitian, with follow-ups for 3 months. The plan is based on Dietary Reference Intakes and adapted to Parkinson's disease and constipation management guidelines.

Behavioral: Dietitian-Guided Nutritional Intervention

Control Group

NO INTERVENTION

Participants will not receive individualized nutritional support during the study period. They will receive the dietary guidance only after the end of the study (3 months).

Interventions

Dietitian-Guided Nutritional Intervention BEHAVIORAL

Participants receive a diet plan and nutritional counseling provided by a registered dietitian, based on a standardized protocol aligned with the Dietary Reference Intakes (DRIs) and adapted for the management of Parkinson's disease and constipation. The intervention includes follow-ups with the dietitian over a 3-month period.

Also known as: Diet plan

Nutritional Intervention Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Hospital de Clinicas de Porto Alegre: lead

Study Sites (1)

Hospital de Clínicas de Porto Alegre (HCPA)

Porto Alegre, Rio Grande do Sul, Brazil

Location

Related Publications (4)

• National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee on the Dietary Reference Intakes for Energy. Dietary Reference Intakes for Energy. Washington (DC): National Academies Press (US); 2023 Jan 17. Available from http://www.ncbi.nlm.nih.gov/books/NBK588659/

  PMID: 36693139 BACKGROUND

• Barichella M, Cereda E, Cassani E, Pinelli G, Iorio L, Ferri V, Privitera G, Pasqua M, Valentino A, Monajemi F, Caronni S, Lignola C, Pusani C, Bolliri C, Faierman SA, Lubisco A, Frazzitta G, Petroni ML, Pezzoli G. Dietary habits and neurological features of Parkinson's disease patients: Implications for practice. Clin Nutr. 2017 Aug;36(4):1054-1061. doi: 10.1016/j.clnu.2016.06.020. Epub 2016 Jul 5.

  PMID: 27406858 BACKGROUND

• Drossman DA, Hasler WL. Rome IV-Functional GI Disorders: Disorders of Gut-Brain Interaction. Gastroenterology. 2016 May;150(6):1257-61. doi: 10.1053/j.gastro.2016.03.035. No abstract available.

  PMID: 27147121 BACKGROUND

• Postuma RB, Berg D, Stern M, Poewe W, Olanow CW, Oertel W, Obeso J, Marek K, Litvan I, Lang AE, Halliday G, Goetz CG, Gasser T, Dubois B, Chan P, Bloem BR, Adler CH, Deuschl G. MDS clinical diagnostic criteria for Parkinson's disease. Mov Disord. 2015 Oct;30(12):1591-601. doi: 10.1002/mds.26424.

  PMID: 26474316 BACKGROUND

MeSH Terms

Conditions

Parkinson Disease; Constipation

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases; Signs and Symptoms, Digestive; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Maira Rozenfeld Olchik, PhD

  Federal University of Rio Grande do Sul

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Maira Rozenfeld Olchik, PhD

CONTACT

+55 (51) 33083020; molchik@hcpa.edu.br

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 2, 2025
• First Posted: October 9, 2025
• Study Start: October 1, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): August 1, 2029
• Last Updated: October 9, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

BR (1)