Overview
This is a 10-week randomized, controlled study to compare the safety and efficacy of two common fiber supplements, psyllium and wheat bran in terms of changes in body weight, nutrition status, and bowel function in patients with Parkinson's Disease who have constipation symptoms. After a 2-week run-in period, participants will be randomized to receive 10 grams daily of psyllium, coarse wheat bran, or maltodextrin (placebo) for 8 weeks. Nutritional and neurological evaluations will be conducted at the beginning and end of the 8-week intervention period.
Eligibility
Inclusion Criteria:
- Physician-diagnosed Parkinson's disease
- Age 40-85 years
- Drug naïve or on stable dosage of PD medications with no plans to change for the duration of the study protocol
- Hoehn & Yahr stage < 4 in the clinical "ON" state
- Using laxatives (Miralax, Dulcolax, sennosides, etc.) regularly over the past 1 months (≥ 2 days per week)
- Complete informed consent in English
- Maintain habitual diet and exercise routine throughout study period
- Consume the study intervention twice per day during the eight-week intervention period
- Complete daily and weekly questionnaires, and all dietary recalls over approximately 10 weeks
- Fast (no food or drink, except plain water, coffee, or tea) at least 12 hours before each study visit
Exclusion Criteria:
- Atypical or secondary Parkinsonism
- Underweight (BMI <18.5)
- Inability to swallow study supplement due to swallowing concerns
- Currently using a fiber supplement
- Use of another investigational product within 3 months of the screening visit
- Being treated for a physician-diagnosed GI disease or condition other than constipation, gastroparesis, gastroesophageal reflux disease, or diverticular disease