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Microbiota Intervention to Change the Response of Parkinson's Disease

NCT03575195 · Status: SUSPENDED · Phase: PHASE1/PHASE2 · Type: INTERVENTIONAL · Enrollment: 86

Last updated 2025-09-04

No results posted yet for this study

Summary

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.

Conditions

  • Parkinson Disease

Interventions

DRUG

Rifaximin

Rifaximin 550mg orally

OTHER

Placebo

Placebo control

Sponsors & Collaborators

Principal Investigators

  • Caroline Tanner, MD, PhD · University of California, San Francisco

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Model
PARALLEL

Eligibility

Min Age
30 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2019-07-15
Primary Completion
2026-08-31
Completion
2026-08-31
FDA Drug
Yes

Countries

  • United States

Study Locations

More Related Trials

Entities

Companies

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT03575195 on ClinicalTrials.gov