Microbiota Intervention to Change the Response of Parkinson's Disease (MICRO-PD)

The clinical phenotype of Parkinson's disease (PD) is quite variable, as is the response to and side effects from medications. While many patients respond to carbidopa/levodopa early on, motor fluctuations and dyskinesias can become a problem as the condition progresses, causing significant impairment in function and quality of life. The gut microbiome is of increasing interest in PD, potentially contributing to pathophysiology and clinical phenotype. Furthermore, gut bacteria are capable of metabolizing levodopa, which may decrease its ability to reach the central nervous system and could explain the variable effect seen clinically. Altering the population of drug-metabolizing bacteria could improve the clinical symptoms of PD and the benefit seen with medications. The investigators hypothesize that the gut microbiome in people with PD correlates with their phenotypic characteristics, which can be improved with targeting the microbiome through dietary or therapeutic interventions. The investigators propose a two-part clinical trial. First, a cross-sectional analysis will correlate the microbiome profile with (a) the clinical phenotype of PD and (b) medication response. Second, a randomized, controlled trial, will evaluate the effect of microbiome manipulation on clinical phenotype and medication response. The investigators plan to reduce the level of bacteria through antibiotic use, resetting the potentially disadvantageous microbiome population. Outcomes will include changes in clinical symptoms, alterations in the the microbiome, and changes in serum markers of inflammation. This thorough characterization will broaden our understanding of the gut-brain axis significantly in PD in clinically relevant ways that have yet to be explored.

Study Overview

• Status: Recruiting
• Conditions: Parkinson Disease
• Intervention / Treatment: Other: Placebo; Drug: Rifaximin

• Study Type: Interventional
• Enrollment (Anticipated): 86
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Hannah McCarthy Potter, BA; Phone Number: 415-514-6257; Email: Hannah.MccarthyPotter@ucsf.edu
• Study Contact Backup: Name: Ethan Brown, MD; Phone Number: 415-514-6257; Email: ethan.brown@ucsf.edu

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94115
      • Recruiting
      • University of California San Francisco
      • Contact: Hannah McCarthy Potter, BA; Phone Number: 415-514-6257; Email: Hannah.MccarthyPotter@ucsf.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Parkinson's disease
• Stable on levodopa therapy with fluctuations

Exclusion Criteria:

• Chronic gastrointestinal disease
• Recent antibiotic or probiotic therapy
• Pregnant
• Immunocompromised

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Matching placebo	Other: Placebo; Placebo control
Experimental: Intervention; Rifaximin	Drug: Rifaximin; Rifaximin 550mg orally

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MDS-UPDRS Part III	The Movement Disorders Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is a validated scale that quantifies many of the symptoms and signs of Parkinson's disease. Part III in particular focuses on the motor symptoms of Parkinson's disease through a neurologic exam. The exam is often performed when medications are held for 8-12 hours (the "OFF" state) and again when medications are given and providing therapeutic benefit (the "ON" state), and the difference between scores is calculated. The scale goes from a minimum of 0 to a maximum of 132. There is no specific cutoff, but a higher score indicates a higher severity of symptoms. The trial will examine the change in the MDS-UPDRS Part III both OFF and ON medication after the intervention.	Two weeks
Percent of OFF time according to home motor diaries	Patients with Parkinson's disease often have times where levodopa is providing therapeutic benefit and times when it is not. "OFF" time indicates the times of day where levodopa therapy is not providing therapeutic benefit. An outcome of the trial will be the change in medication OFF time that the participant experiences at home, according to motor diaries.	Two weeks

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Collaborators: Nova Southeastern University; Gateway Institute for Brain Research

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2019
• Primary Completion (Anticipated): December 1, 2023
• Study Completion (Anticipated): December 1, 2023

Study Registration Dates

• First Submitted: June 21, 2018
• First Submitted That Met QC Criteria: June 21, 2018
• First Posted (Actual): July 2, 2018

Study Record Updates

• Last Update Posted (Actual): March 2, 2023
• Last Update Submitted That Met QC Criteria: February 28, 2023
• Last Verified: February 1, 2023

More Information

Terms related to this study

• 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; Anti-Infective Agents; Gastrointestinal Agents; Anti-Bacterial Agents; Rifaximin
• Other Study ID Numbers: 17-22841

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes