NCT06718686 · Phase 1 · RECRUITING
Rifaximin SSD in Dementia Trial
This trial is testing a new low-dose formulation of rifaximin, an antibiotic that stays in the gut rather than entering the bloodstream, to see whether it can shift gut bacteria in a more favorable direction in people who already have mild to moderate Alzheimer's or vascular dementia. It is a Phase 1 trial, meaning the primary goals are safety and tolerability, not proving the treatment works.
You may qualify if
- Probable Alzheimer's Disease (AD) or Vascular Dementia (VaD) mild or moderate based on Clinical Dementia Rating Scale.
- Males and Females Age ≥ 65 years
- Community living with availability of caregiver to accompany participant to study visits and to participate in the study.
- Able to consent or legal guardian who can consent (with participant assent).
- Legally authorized representative (LAR) and caregiver for the study is the same individual.
- Fluency (both participant and caregiver) in written and spoken English to participate in study visits.
You're excluded if
- Dementia not due to AD or VaD
- Clinically significant agitation or aggression (requiring treatment with antipsychotic medication)
- Delusions and/or hallucinations
- Severe psychopathology including major depression
- Unstable, severe, or poorly controlled medical conditions evident from physical examination or clinical history
- Visual and/or hearing disorder that prevents completion of neuropsychologic evaluations.
- Diarrhea
- Hypersensitivity to rifaximin, components of rifaximin,
- and any rifamycin antimicrobial agent
- Antibiotic use in the prior 6 months
- Taking medications that interact with Rifaximin. P-glycoprotein (P-gp) inhibitor treatment is permitted as long as the use of P-gp inhibitors is discussed with the investigator.
- History of alcohol and/or drug abuse
- Participation in another investigational drug trial in the last 30 days
The sponsor's own eligibility wording, lightly reformatted. The study team makes the final eligibility decision — worth discussing with your doctor.
Eligibility criteria as of 2026-04-03