Mediterranean Diet Intervention to Improve Gastrointestinal Function in Parkinson's Disease a Randomized, Controlled, Clinical Trial (MEDI-PD)

Mediterranean Diet Intervention to Improve Gastrointestinal Function in Parkinson's Disease: a Randomized, Controlled, Clinical Trial

This is a 10-week randomized, controlled study to investigate the effect of a Mediterranean diet intervention on gastrointestinal function in Parkinson's disease. After a 2-week run-in period, participants will be instructed to receive standard of care for constipation or receive standard of care + follow a Mediterranean diet for 8 weeks and answer daily and weekly questionnaires. Nutritional and neurological evaluations and stool samples will be collected at 0, 4 and 8 weeks.

Study Overview

• Status: Completed
• Conditions: Parkinson Disease
• Intervention / Treatment: Other: Standard of care + Mediterranean diet (intervention); Other: Standard of care (control)

• Study Type: Interventional
• Enrollment (Actual): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32611
      • University of Florida

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 85 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Physician-diagnosed Parkinson's disease aged 40-85 years
• Drug naïve or on stable dosage of Parkinson's medications with no plans to change for the duration of the study protocol
• Hoehn & Yahr stage =<2.5 in the clinical "ON" state
• Constipation syndrome scores >=2.0 based on the GSRS
• Consume <20 grams of fiber daily based on the Block Fruit/Vegetable/Fiber screener
• Able to complete informed consent in English
• Willing to maintain habitual diet through the pre-baseline period.
• Willing to make dietary changes to follow a Mediterranean diet and/or receive standard of care for constipation during the intervention period.
• Willing to complete daily and weekly questionnaires and 12 dietary recalls over approximately 10 weeks.
• Able to provide stool samples during the study collection periods.
• Willing to avoid strenuous exercise and alcohol such as beer, wine, and cocktails 24 hours prior to each of the 3 study visits.
• Able to fast (no food or drink, except water, or decaf tea) at least 12 hours before each study visit
• Willing to discontinue taking prebiotic, herbal, or high-dose vitamin or mineral supplements that may impact inflammation during the pre-baseline period and throughout the study protocol.

Exclusion Criteria:

• Atypical or secondary Parkinsonism
• Underweight (BMI <18.5)
• History of deep brain stimulation (DBS) surgery
• Regular use of enemas or suppositories to alleviate constipation (e.g., >1 time per week)
• Use of another investigational product within 3 months of the screening visit
• Antibiotic or probiotic supplement use within 2 months from the day of stool collection
• Currently being treated for a physician-diagnosed GI disease or condition other than constipation, irritable bowel disease, gastroparesis, reflux or diverticular disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Standard of Care + Mediterranean Diet; Participants will be given standard of care for constipation (handout) plus individualized diet education on the Mediterranean diet and instructed to follow the diet during the 8-week intervention period. Diet education will be administered by a study dietitian and followed with weekly phone calls to ensure compliance, improve adherence to the diet and monitor for adverse events.	Other: Standard of care + Mediterranean diet (intervention); Participants will receive a constipation management handout that is distributed regularly to patients who present with constipation symptoms at an outpatient neurology clinic. The handout recommends increasing fluids daily, as well as increasing physical activity and dietary fiber intake. Laxative medications and recommendations for usage are included. Participants will be instructed to include the following in their diet: a) abundant use of olive oil for cooking and dressing dishes; b) consume ≥2 daily servings of vegetables; c) ≥2-3 daily serving of fruits; d) ≥3 weekly servings of legumes; e) ≥3 weekly servings of fish/seafood; f) ≥3 weekly serving of nuts/seeds; g) select white instead of red or processed meats; h) cook at least twice a week with sofrito. Limit consumption of cream, butter, processed meat, sugared beverages, industrial bakery products and desserts, and French fries or chips. For usual drinkers, the main source of alcohol should be wine.
ACTIVE_COMPARATOR: Standard of Care; Participants will be given standard of care for constipation (handout) to utilize during the 8-week intervention period. A study dietitian will follow up with weekly phone calls to support adherence and monitor for adverse events.	Other: Standard of care (control); Participants will receive a constipation management handout that is distributed regularly to patients who present with constipation symptoms at an outpatient neurology clinic. The handout recommends increasing fluids daily, as well as increasing physical activity and dietary fiber intake. Laxative medications and recommendations for usage are included.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
GSRS Constipation Syndrome Score	The difference between mean change (final - baseline) in constipation syndrome scores for the Med diet versus control diet.	10 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stool Frequency	Compare the number of stools between the intervention and control groups	Each week up to 10 weeks
Stool Form	Compare stool form, as measured by the Bristol Stool Form Scale (BSFS), between the intervention and control groups. The BSFS is scored between 1 (hard stool) - 7 (liquid stool).	Each day up to 10 weeks
Laxative Usage	Compare number of days using laxative medications between the intervention and control groups.	Each week up to 10 weeks
Digestive Health	Weekly GI symptoms assessed using the Gastrointestinal Symptom Rating Scale (GSRS). The GSRS consists of 15 questions related to 5 syndromes, constipation, diarrhea, reflux, abdominal pain, and indigestion. Symptoms are scored 1=no discomfort to 7=very severe discomfort. Scores from each of the 15 questions are summed for the total GSRS score.	Every week up to 10 weeks
Quality of Life Related to Digestive Health	Weekly GI experiences assessed using an in-house Digestion-Associated Quality of Life questionnaire.	Every week up to 10 weeks
Fecal Microbial Diversity	Changes in fecal microbial composition and diversity (i.e. alpha and beta diversity) will be assessed.	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Fecal Microbial Quantitative Polymerase Chain Reaction (qPCR)	Changes in fecal microbial composition to quantify bacterial species of interest (e.g., F. prausnitzii, Prevotella, Roseburia, Bilophila, Akkermansia, etc.) will be assessed.	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Intestinal Inflammation and Permeability	Changes in fecal calprotectin and zonulin will be assessed using enzyme-linked immunosorbent assay	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mediterranean diet adherence	Compare Mediterranean diet adherence scores using the 14-Item Mediterranean diet adherence screener (MEDAS) between groups	Each week up to 10 weeks
Dietary Fiber Intake	Changes in dietary fiber intake as measured by averaged 4-day dietary recalls using the Automated Self-Administered 24-hour dietary recall (ASA-24) between groups	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Body weight	Changes in body weight between groups	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Body Composition (Fat Free Mass)	Changes in fat free mass using bio-impedance spectroscopy (BIS) between groups	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Handgrip strength	Changes in handgrip strength will be assessed using a hand dynamometer between groups	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Quality of Life (QOL)	Changes in QOL will be assessed using the Parkinson's Disease Quality of life -39 (PDQ-39)	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Anxiety	Changes in symptoms of anxiety will be assessed using the Hamilton Anxiety Rating Scale	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Depression	Changes in symptoms of anxiety will be assessed using the Hamilton Depression Rating Scale	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)
Physical Activity	Changes in MET minutes will be assessed using the International Physical Activity Questionnaire (IPAQ).	Baseline (Week 0); Midpoint (Week 4); Final (Week 8)

Collaborators and Investigators

• Sponsor: University of Florida

Publications and helpful links

General Publications

• Rusch C, Beke M, Tucciarone L, Dixon K, Nieves C Jr, Mai V, Stiep T, Tholanikunnel T, Ramirez-Zamora A, Hess CW, Langkamp-Henken B. Effect of a Mediterranean diet intervention on gastrointestinal function in Parkinson's disease (the MEDI-PD study): study protocol for a randomised controlled trial. BMJ Open. 2021 Sep 22;11(9):e053336. doi: 10.1136/bmjopen-2021-053336.

Study record dates

Study Major Dates

• Study Start (ACTUAL): February 8, 2021
• Primary Completion (ACTUAL): June 7, 2022
• Study Completion (ACTUAL): June 7, 2022

Study Registration Dates

• First Submitted: December 17, 2020
• First Submitted That Met QC Criteria: December 23, 2020
• First Posted (ACTUAL): December 24, 2020

Study Record Updates

• Last Update Posted (ACTUAL): July 12, 2022
• Last Update Submitted That Met QC Criteria: July 11, 2022
• Last Verified: July 1, 2022

More Information

Terms related to this study

• Keywords: Inflammation; Constipation; Microbiome; Mediterranean diet
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Parkinsonian Disorders; Basal Ganglia Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases; Parkinson Disease
• Other Study ID Numbers: IRB202001333

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The anonymized datasets used and/or analyzed during the study will be available from the corresponding author upon reasonable request and approval of the University of Florida.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No