NCT03575195SuspendedPhase 1/2
Microbiota Intervention to Change the Response of Parkinson's Disease
Source: ClinicalTrials.gov · Last updated 4 Sept 2025
Reason given: Conducting an interim analysis
Brief summary (registry, in English)
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.
- Status (registry)
- Suspended
- Phase (registry)
- Phase 1/2
- Study type
- Interventional
- Enrollment
- 86 (estimated)
- First submitted
- 21 Jun 2018
- Start date
- 15 Jul 2019
- Primary completion date
- Aug 2026
- Lead sponsor
- University of California, San Francisco
- Diseases
- Parkinson disease
- NCT number
- NCT03575195
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Recent antibiotic or probiotic therapy
Other illness
- Chronic gastrointestinal disease
Other
- Pregnant
- Immunocompromised
Who the study is looking for
- Parkinson's disease
- Stable on levodopa therapy with fluctuations
Age in the registry: 30 years to - · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| University of California San Francisco | San Francisco | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.