Dementia Alzheimer TypePhase 1/2RIDENCT06718686
Rifaximin SSD in Dementia Trial
A Phase 1/2 study testing Rifaximin SSD 40 mg IR tablet in people with Dementia Alzheimer Type and Dementia Associated With Cerebrovascular Disease, run by Jasmohan Bajaj at 1 site in United States.
Trial summary
Using a new formulation of rifaximin, a non-absorbable antibiotic, to test if it can affect microbes in the gut of patients with dementia favorably. Read more about this study
- Who is it for?
- Ages 65 years and older
- Conditions the study is for
- Dementia Alzheimer Type, Dementia Associated With Cerebrovascular Disease
- What is being tested?
- Rifaximin SSD 40 mg IR tablet
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 30 Dec 2024to 30 Dec 2027
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 years and older
- All sexes
- No healthy volunteers
- Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Show all 13Show fewer
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Richmond VA Medical Center
Richmond, Virginia, 23249
Haley Obolewicz, RN, 804-675-5000 ext. 15705, haley.obolewicz@va.gov
About this study
Official title: Rifaximin in Dementia Trial (RIDE): Gut-Brain Modulation With Rifaximin SSD in Dementia
Using a new formulation of rifaximin, a non-absorbable antibiotic, to test if it can affect microbes in the gut of patients with dementia favorably.
Read the detailed description
Hypothesis: Rifaximin SSD therapy is safe and well tolerated in patients with AD and VaD with beneficial changes in systemic inflammation and systemic biomarkers of dementia due to improvement in microbiota function compared to placebo-related changes in a single-blind, placebo-controlled Phase 1b/2a trial .
Overall Objective: In a single blind placebo-controlled trial in patients with Alzheimer's or vascular dementia, to determine the effect of rifaximin SSD compared to placebo on gut microbial structure and function, cognitive and daily function, and caregiver burden.
- Being tested
- Rifaximin SSD 40 mg IR tablet, Placebo
- Keywords
- dementia, rifaximin, gut-brain, Alzheimer's, vascular dementia
- Medical subject headings
- Alzheimer Disease, Dementia, Dementia, Vascular
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Rifaximin SSD 40 mg IR tabletDrug
Drug therapy vs placebo
PlaceboDrug
Placebo drug
| Study group | Role | What they receive |
|---|---|---|
| Placebo | Placebo comparator | Patients will be given placebo and actual drug sequentially with the order hidden Receives: Drug: Placebo |
| Rifaximin SSD 40mg IR BID | Experimental | Patients will be given placebo and actual drug sequentially with the order hidden Receives: Drug: Rifaximin SSD 40 mg IR tablet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in stool and serum short-chain fatty acid levels
Change in SCFA in stool and serum in rifaximin SSD phase vs placebo phase
Measured: 10 weeks
Change in bile acids in stool and serum
Change in bile acids in stool and serum in rifaximin SSD phase vs placebo phase
Measured: 10 weeks
Secondary outcomes (14)
Systemic inflammatory change
serum lipopolysaccharide-binding protein (LBP), inflammatory cytokines (IL-6, TNF-α, IL-10, IL-1β) in placebo phase vs Rifaximin SSD phase
Measured: 10 weeks
Stool microbiome composition
16SrRNA microbiome composition and diversity change in placebo vs Rifaximin SSD phase
Measured: 10 weeks
Change in dementia biomarkers
Plasma concentrations of Aβ42 and Aβ40 to calculate amyloid-β (Aβ)42/40 ratio and plasma concentration of phospho-tau (p-tau)181 in placebo vs Rifaximin SSD phase
Measured: 10 weeks
MMSE
Change in MMSE between the 2 phases
Measured: 10 weeks
Cognitive testing using Psychometric Hepatic Encephalopathy Score
Change in PHES in placebo vs rifaximin SSD phase
Measured: 10 weeks
Clinical Dementia Rating - Sum of Boxes (CDR-SB)
Change in CDR-SB in placebo vs Rifaximin SSD phase
Measured: 10 weeks
EncephalApp Stroop performance
Change in off time and on time in seconds between placebo and rifaximin SSD phases
Measured: 10 weeks
Critical flicker fusion analysis
change in threshold to see CFF fusion in rifaximin SSD vs placebo phases
Measured: 10 weeks
Katz Index of Independence in Activity of Daily Living (ADL)
change in the score above judged by caregivers in placebo vs Rifaximin SSD phase
Measured: 10 weeks
Lawton-Brody Instrumental Activities of Daily Living (IADL)
Change in instrument score above by caregivers in rifaximin SSD vs placebo phase
Measured: 10 weeks
Zarit Burden Interview short form
Change in instrument score above by caregivers in rifaximin SSD vs placebo phase
Measured: 10 weeks
Sickness Impact profile
change in score of the QOL instrument above in placebo vs rifaximin SSD phases
Measured: 10 weeks
PROMIS-29
change in score of the QOL instrument above in placebo vs rifaximin SSD phases
Measured: 10 weeks
Safety
Serious adverse event rates in placebo versus rifaximin SSD phases
Measured: 10 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Dec 2024
- Study start30 Dec 2024
- Primary completion30 Oct 2027 (estimated)
- Study completion30 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dementia Alzheimer TypeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jasmohan Bajaj
- Sponsor type
- US federal agency
- Collaborators
- Bausch Health Americas, Inc.
- Responsible party
- Sponsor-investigator, Jasmohan Bajaj, Hunter Holmes Mcguire Veteran Affairs Medical Center
- Investigators
- Jasmohan Bajaj, Principal investigator, Richmond VA Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06718686
- Sponsor's protocol ID
- 1817324
- Acronym
- RIDE
- Status last verified
- Apr 2026
- First submitted
- 2 Dec 2024
- Last updated
- 3 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Not IRB approved to do so
Study at a glance
From the registry record, last updated by the sponsor on 3 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Rifaximin in Dementia Trial (RIDE): Gut-Brain Modulation With Rifaximin SSD in Dementia
- ClinicalTrials.gov ID
- NCT06718686
- Acronym / sponsor ID
- RIDE / 1817324
- Keywords
- dementia, rifaximin, gut-brain, Alzheimer's, vascular dementia
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Jasmohan BajajUS federal agency
- Collaborators
- Bausch Health Americas, Inc.
- Study start
- 30 Dec 2024 (actual)
- Primary completion
- 30 Oct 2027 (estimated)
- Study completion
- 30 Dec 2027 (estimated)
- First posted
- 5 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Using a new formulation of rifaximin, a non-absorbable antibiotic, to test if it can affect microbes in the gut of patients with dementia favorably.
Detailed description
Hypothesis: Rifaximin SSD therapy is safe and well tolerated in patients with AD and VaD with beneficial changes in systemic inflammation and systemic biomarkers of dementia due to improvement in microbiota function compared to placebo-related changes in a single-blind, placebo-controlled Phase 1b/2a trial .
Overall Objective: In a single blind placebo-controlled trial in patients with Alzheimer's or vascular dementia, to determine the effect of rifaximin SSD compared to placebo on gut microbial structure and function, cognitive and daily function, and caregiver burden.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Placebo | Placebo comparator | Drug: PlaceboPatients will be given placebo and actual drug sequentially with the order hidden |
| Rifaximin SSD 40mg IR BID | Experimental | Drug: Rifaximin SSD 40 mg IR tabletPatients will be given placebo and actual drug sequentially with the order hidden |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (13 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Rifaximin SSD 40 mg IR tabletDrug therapy vs placebo | Drug | Rifaximin SSD 40mg IR BID |
| PlaceboPlacebo drug | Drug | Placebo |
Primary outcome
Change in stool and serum short-chain fatty acid levels
Time frame: 10 weeks
Change in SCFA in stool and serum in rifaximin SSD phase vs placebo phase
Change in bile acids in stool and serum
Time frame: 10 weeks
Change in bile acids in stool and serum in rifaximin SSD phase vs placebo phase
14 secondary outcomes
Systemic inflammatory change
Time frame: 10 weeks
Stool microbiome composition
Time frame: 10 weeks
Change in dementia biomarkers
Time frame: 10 weeks
MMSE
Time frame: 10 weeks
Cognitive testing using Psychometric Hepatic Encephalopathy Score
Time frame: 10 weeks
Clinical Dementia Rating - Sum of Boxes (CDR-SB)
Time frame: 10 weeks
EncephalApp Stroop performance
Time frame: 10 weeks
Critical flicker fusion analysis
Time frame: 10 weeks
Katz Index of Independence in Activity of Daily Living (ADL)
Time frame: 10 weeks
Lawton-Brody Instrumental Activities of Daily Living (IADL)
Time frame: 10 weeks
Zarit Burden Interview short form
Time frame: 10 weeks
Sickness Impact profile
Time frame: 10 weeks
PROMIS-29
Time frame: 10 weeks
Safety
Time frame: 10 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Apr 2026.
- Individual participant dataSharing planned: No. Not IRB approved to do so
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jasmohan Bajaj principal investigator
Richmond VA Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Rifaximin SSD 40 mg IR tablet in people with Dementia Alzheimer Type and Dementia Associated With Cerebrovascular Disease, run by Jasmohan Bajaj at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jasmohan S Bajaj, MD (804-675-5802, jasmohan.bajaj@vcuhealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in stool and serum short-chain fatty acid levels (time frame: 10 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Apr 2026; AzTrials last refreshed its copy on 3 Nov 2026.