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Microbiota Intervention to Change the Response of Parkinson’s Disease


Brief 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.


Inclusion Criteria:

– Parkinson’s disease

– Stable on levodopa therapy with fluctuations

Exclusion Criteria:

– Chronic gastrointestinal disease

– Recent antibiotic or probiotic therapy

– Pregnant

– Immunocompromised


  • University of California San Francisco, San Francisco, California, United States, 94115
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