Weight Loss in Parkinson's Disease and Role of Small Bowel Bacterial Overgrowth


About this study

The potential role of Small bowel bacterial overgrowth (SBBO) in weight loss occurring in patients with PD has not previously been examined. Our hypothesis is that SBBO is an important contributor to the development of weight loss in individuals with Parkinson's disease. The investigators propose to 1) examine the role of SBBO in weight loss occurring in patients with PD and 2) determine the response to its treatment with a poorly absorbed antibiotic. The investigators propose to perform a prospective, observational case-control study with an open-label therapeutic component. Cases will be defined as those PD patients who've experienced significant weight loss while Controls will be defined as those PD patients who have not experienced significant weight loss.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion criteria:

  1. Parkinson's Disease

Exclusion Criteria:

  1. Wheelchair-bound, akinetic individuals
  2. Tube-fed individuals
  3. Presence of dementia
  4. Unwilling or unable to complete the tests
  5. Allergic or intolerant to rifaximin
  6. Presence of chronic upper or lower gastrointestinal disorders that have symptoms that may be confused with SBBO (e.g., irritable bowel syndrome, inflammatory bowel disease, celiac disease, functional dyspepsia, gastroparesis, and chronic pancreatitis)
  7. Presence of prior surgery on the gastrointestinal tract except cholecystectomy, appendectomy or herniorrhaphy
  8. Presence of severe concomitant acute or chronic medical condition that may interfere with the completion or interpretation of the test results
  9. Women of childbearing potential. Given the age of patients with Parkinson's disease, we do not anticipate this being a large population.
  10. Use of antibiotics within 1 month of breath testing

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

John DiBaise, M.D.

Closed for enrollment

More information


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