IBS (Irritable Bowel Syndrome)Early Phase 1CURE-IBS-DNCT07238790
Use of A Complex Gut Bacterial Consortium (MITI 001) for the Treatment of Irritable Bowel Syndrome With Diarrhea
A Early Phase 1 study testing MITI-001 administration in people with IBS (Irritable Bowel Syndrome) and Diarrhea, run by Stanford University at 2 sites in United States.
Trial summary
While the pathophysiology of diarrhea-predominant irritable bowel syndrome (IBS-D) is complex and heterogeneous, dysbiosis of the gut microbiome is frequently observed, suggesting that a substantial subset of patients with irritable bowel syndrome (IBS) have symptoms that are initiated and/or perpetuated by a… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- IBS (Irritable Bowel Syndrome), Diarrhea
- What is being tested?
- MITI-001 administration
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 2 sitesUnited States
- Study dates
- Dec 2025to Dec 2030
- Phase
- Early Phase 1
- 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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18 to 65 years inclusive at the time of signing the informed consent.
- Diagnosis of IBS-D according to the Rome IV criteria (Lacy 2017).
- At least 1 of the following measures of microbiome dysfunction:
- Primary bile acid proportion ≥ 12% in stool samples, or
- Positive hydrogen breath test (with either glucose or lactulose substrate) (Rezaie 2017)
- Normal C-reactive protein level
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- Gallbladder intact
- Willing to use appropriate contraception during the treatment period and for one week after the last study visit.
- Male participants with partners who are women of childbearing potential (WOCBP): Appropriate contraception includes condoms or other means considered adequate by the responsible Investigator.
- Female participants who are WOCBP: Appropriate contraception includes condoms, an intrauterine device, hormonal contraception, or other means considered adequate by the responsible Investigator.
- Capable of giving signed informed consent as described in Appendix 1, which includes compliance with the requirements and restrictions listed in the informed consent form and in this protocol.
- Able to tolerate the planned course of antibiotics, EGD, and colonoscopy with bowel lavage.
Who cannot join
- Inflammatory bowel disease
- Untreated enteric infections
- History of gastrointestinal (GI) surgery: All participants with GI surgeries below the pylorus will be excluded from this study. This includes participants with a history of colectomy, segmental colonic resection, and small bowel resections.
- Documented severe gastroparesis
- Active intestinal obstruction
- Dysphagia (oropharyngeal, esophageal, functional, or neuromuscular)
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- History of recurrent aspiration episodes
- Any conditions associated with a high risk of bleeding, including but not limited to coagulopathy/bleeding disorder, severe liver disease, active or recent GI bleeding, or recent abdominal or other GI surgery
- Active diagnosis of major depressive disorder
- Severe immunodeficiency, inherited or acquired (e.g., human immunodeficiency virus, active chemotherapy or immunosuppressive medications [including steroids, biologic therapy, or bone marrow suppressive agent], or radiation therapy)
- Any other significant medical condition that could confound or interfere with evaluation of safety or tolerability or prevent compliance with the study protocol at the discretion of the Investigator
- Active antibiotic use (except protocol-specified antibiotics)
- Active treatment with high levels of immunosuppressive therapies (active chemotherapy or immunosuppressive medications [including steroids, biologic therapies, or bone marrow suppressive agents], or radiation therapy)
- Active anticoagulant or antiplatelet therapy, or use of other medications associated with a high risk of bleeding within 48 hours prior to endoscopy on Day 1
- Use of a probiotic within one month prior to dosing of MITI-001 on Day 1
- Simultaneous participation in another interventional clinical trial
- Renal insufficiency (estimated glomerular filtration rate < 50 mL/min)
- Absolute neutrophil count < 1000 μL, platelet count < 50 × 109/L, or hemoglobin level < 6.5 g/dL
- Pregnant, breastfeeding, or planning pregnancy during the study period
- Active drug or alcohol use disorder
- Known allergy or anaphylaxis to vancomycin, metronidazole, ciprofloxacin, or polyethylene glycol
- Inability to comply with research requirements
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Clinical Research Coordinator contact
United States2 sites
Stanford Digestive Health Clinic
Redwood City, California, 94063
Stanford University
Stanford, California, 94305
About this study
Official title: A Phase 1 Study to Evaluate the Safety of a Complex Gut Bacterial Consortium (MITI 001) for the Treatment of Irritable Bowel Syndrome With Diarrhea
While the pathophysiology of diarrhea-predominant irritable bowel syndrome (IBS-D) is complex and heterogeneous, dysbiosis of the gut microbiome is frequently observed, suggesting that a substantial subset of patients with irritable bowel syndrome (IBS) have symptoms that are initiated and/or perpetuated by a microbiome dysfunction. Successful randomized controlled trials (RCT) for IBS-D (Ford 2018; Black 2022) leveraging microbiome-targeted therapies (antibiotics or low microbiome fermentation diets) suggest the gut microbiome is at least partially involved in IBS symptoms. Furthermore, fecal microbiota transplantation (FMT) for patients with IBS-D has demonstrated promising results (El-Salhy 2020), supporting the possibility that altering the microbiome composition could ameliorate IBS-D symptoms.
MITI-001 is a transplantable gut bacterial community composed of 157 live bacterial strains, encompassing 79 genera of commensal bacteria, that have been isolated from healthy donor stool, purified, and banked. The hypothesis of the proposed research is that MITI-001 can target the pathophysiologic lesion in a subset of IBS-D patients, restore the altered microbial metabolic process, and thus alleviate IBS-D symptoms.
Read the detailed description
MITI-001 has not yet been tested in humans. However, several RCTs support the role of the gut microbiome in IBS-D pathogenesis. These include trials involving non-absorbable antibiotics (e.g., rifaximin) and low-fermentation diets (Ford 2018; Black 2022), which have demonstrated symptom improvement. FMT has also shown promising efficacy in IBS-D (El-Salhy 2020), particularly when pre-treatment with antibiotics and/or bowel lavage was used to deplete the resident microbiota (Ianiro 2022; Zhang 2024). These findings highlight the need for introduction of a complete microbial ecosystem, rather than enrichment of isolated species, to achieve stable engraftment and functional restoration.
MITI-001 is uniquely designed to address both the compositional and functional deficiencies observed in a subset of IBS-D patients. It contains bacterial species capable of bile acid metabolism (bile salt hydrolase and 7α-dehydroxylation), potentially restoring the physiological bile acid pool. Given that isolated supplementation of missing species has been insufficient due to niche occupancy and dysbiosis, a complete defined community is required.
Prior clinical trials have demonstrated a consistent signal suggesting efficacy of FMT (Halkjær 2018; El-Salhy 2020; Aroniadis 2019; Lahtinen 2020; Johnsen 2018; Johnsen 2020; Holvoet 2021). Trials with high-dose endoscopic delivery have been the most successful and support the approach to be used in the proposed study (El-Salhy 2020; Holvoet 2021).
The planned Phase 1, open-label, single-arm, single-center study will evaluate MITI-001, a consortium of 157 live bacterial strains, as a possible treatment for participants with IBS-D. Each study participant will undergo screening assessments, a four-week observation period to quantify baseline symptoms, a nine-day treatment period, and a three-month follow-up period.
During the treatment period, participants will be pre-treated for five consecutive days with a combination of oral broad-spectrum antibiotics (vancomycin, metronidazole, and ciprofloxacin) to decrease the load of existing microbial colonists. One day prior to the first dose of MITI-001, oral antibiotic pre-medication will be stopped, and an orally administered bowel lavage will be performed. On Day 1, one dose of MITI-001 will be administered endoscopically to the duodenum (via esophagogastroduodenoscopy) and one dose will be administered to the ileum/distal colon (via colonoscopy). Participants will then self-administer MITI-001 orally twice daily on Days 2 to 4.
During the follow-up period, participants will have an in-person visit on Day 30 and virtual visits on Days 60 and 90 to monitor symptoms over time and collect stool samples for measurement of engraftment and bile acid composition. Throughout the study, participants will provide information about prior and concomitant medications and adverse events (AEs) via regular telephone or other virtual contacts with the site. A participant diary will be used to collect diet information and symptoms, as well as to administer questionnaires. Stool and urine samples will also be collected by the participant at home and delivered to the site.
- Conditions
- IBS (Irritable Bowel Syndrome), Diarrhea
- Being tested
- MITI-001 administration
- Keywords
- IBS with Diarrhea Predominance (IBS-D)
- Medical subject headings
- Irritable Bowel Syndrome, Diarrhea
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MITI-001 administrationDrug
A complex gut bacterial community (MITI-001) will be given endoscopically and orally
| Study group | Role | What they receive |
|---|---|---|
| Intervention arm (MITI-001) | Experimental | Dosed with MITI-001 Receives: Drug: MITI-001 administration |
What is being measured
The primary outcome is the main question the study is designed to answer.
Determine the safety of MITI-001 in the participant population
Incidence of MITI-001-related adverse events
Measured: up to 90 days
Secondary outcomes (2)
Assess the ability of MITI-001 to restore microbial metabolic function: secondary bile acid metabolism and hydrogen consumption
- Restoration of metabolic normality (i.e., production of DCA and LCA, consumption of hydrogen)
- Engraftment of bai (bile acid-inducible) operon-positive organism(s) measured via metagenomic analysis
- Primary bile acid proportion < 12% in stool
Measured: Day 30 and Day 90
Adequate relief of IBS-D symptoms
- Composite endpoint consisting of:
- 50% or greater reduction in the number of days per week with stools of BSS types 6 or 7
- 30% reduction in the weekly average of the worst daily abdominal pain, for at least 50% of the treatment weeks
Measured: Day 30
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Nov 2025
- Study startDec 2025 (estimated)
- Primary completionDec 2028 (estimated)
- Study completionDec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for IBS (Irritable Bowel Syndrome)Studies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- 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
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 13 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sean Spencer, Stanford University
- Investigators
- Michael Fischbach, PhD, Study director, Stanford UniversitySean P Spencer, MD, PhD, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07238790
- Sponsor's protocol ID
- 82277
- Other IDs
- 31936
- Acronym
- CURE-IBS-D
- Status last verified
- Nov 2025
- First submitted
- 16 Nov 2025
- Last updated
- 20 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1 Study to Evaluate the Safety of a Complex Gut Bacterial Consortium (MITI 001) for the Treatment of Irritable Bowel Syndrome With Diarrhea
- ClinicalTrials.gov ID
- NCT07238790
- Acronym / sponsor ID
- CURE-IBS-D / 82277
- Conditions
- IBS (Irritable Bowel Syndrome), Diarrhea
- Keywords
- IBS with Diarrhea Predominance (IBS-D)
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 13 participants (estimated)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- Dec 2025 (estimated)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2030 (estimated)
- First posted
- 20 Nov 2025 (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.
While the pathophysiology of diarrhea-predominant irritable bowel syndrome (IBS-D) is complex and heterogeneous, dysbiosis of the gut microbiome is frequently observed, suggesting that a substantial subset of patients with irritable bowel syndrome (IBS) have symptoms that are initiated and/or perpetuated by a microbiome dysfunction. Successful randomized controlled trials (RCT) for IBS-D (Ford 2018; Black 2022) leveraging microbiome-targeted therapies (antibiotics or low microbiome fermentation diets) suggest the gut microbiome is at least partially involved in IBS symptoms. Furthermore, fecal microbiota transplantation (FMT) for patients with IBS-D has demonstrated promising results (El-Salhy 2020), supporting the possibility that altering the microbiome composition could ameliorate IBS-D symptoms.
MITI-001 is a transplantable gut bacterial community composed of 157 live bacterial strains, encompassing 79 genera of commensal bacteria, that have been isolated from healthy donor stool, purified, and banked. The hypothesis of the proposed research is that MITI-001 can target the pathophysiologic lesion in a subset of IBS-D patients, restore the altered microbial metabolic process, and thus alleviate IBS-D symptoms.
Detailed description
MITI-001 has not yet been tested in humans. However, several RCTs support the role of the gut microbiome in IBS-D pathogenesis. These include trials involving non-absorbable antibiotics (e.g., rifaximin) and low-fermentation diets (Ford 2018; Black 2022), which have demonstrated symptom improvement. FMT has also shown promising efficacy in IBS-D (El-Salhy 2020), particularly when pre-treatment with antibiotics and/or bowel lavage was used to deplete the resident microbiota (Ianiro 2022; Zhang 2024). These findings highlight the need for introduction of a complete microbial ecosystem, rather than enrichment of isolated species, to achieve stable engraftment and functional restoration.
MITI-001 is uniquely designed to address both the compositional and functional deficiencies observed in a subset of IBS-D patients. It contains bacterial species capable of bile acid metabolism (bile salt hydrolase and 7α-dehydroxylation), potentially restoring the physiological bile acid pool. Given that isolated supplementation of missing species has been insufficient due to niche occupancy and dysbiosis, a complete defined community is required.
Prior clinical trials have demonstrated a consistent signal suggesting efficacy of FMT (Halkjær 2018; El-Salhy 2020; Aroniadis 2019; Lahtinen 2020; Johnsen 2018; Johnsen 2020; Holvoet 2021). Trials with high-dose endoscopic delivery have been the most successful and support the approach to be used in the proposed study (El-Salhy 2020; Holvoet 2021).
The planned Phase 1, open-label, single-arm, single-center study will evaluate MITI-001, a consortium of 157 live bacterial strains, as a possible treatment for participants with IBS-D. Each study participant will undergo screening assessments, a four-week observation period to quantify baseline symptoms, a nine-day treatment period, and a three-month follow-up period.
During the treatment period, participants will be pre-treated for five consecutive days with a combination of oral broad-spectrum antibiotics (vancomycin, metronidazole, and ciprofloxacin) to decrease the load of existing microbial colonists. One day prior to the first dose of MITI-001, oral antibiotic pre-medication will be stopped, and an orally administered bowel lavage will be performed. On Day 1, one dose of MITI-001 will be administered endoscopically to the duodenum (via esophagogastroduodenoscopy) and one dose will be administered to the ileum/distal colon (via colonoscopy). Participants will then self-administer MITI-001 orally twice daily on Days 2 to 4.
During the follow-up period, participants will have an in-person visit on Day 30 and virtual visits on Days 60 and 90 to monitor symptoms over time and collect stool samples for measurement of engraftment and bile acid composition. Throughout the study, participants will provide information about prior and concomitant medications and adverse events (AEs) via regular telephone or other virtual contacts with the site. A participant diary will be used to collect diet information and symptoms, as well as to administer questionnaires. Stool and urine samples will also be collected by the participant at home and delivered to the site.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Intervention arm (MITI-001) | Experimental | Drug: MITI-001 administrationDosed with MITI-001 |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (12 listed)
- Age 18 to 65 years inclusive at the time of signing the informed consent.
- Diagnosis of IBS-D according to the Rome IV criteria (Lacy 2017).
- At least 1 of the following measures of microbiome dysfunction:
- Normal C-reactive protein level
- Gallbladder intact
Key exclusion criteria (22 listed)
- Inflammatory bowel disease
- Untreated enteric infections
- History of gastrointestinal (GI) surgery: All participants with GI surgeries below the pylorus will be excluded from this study. This includes participants with a history of colectomy, segmental colonic resection, and small bowel resections.
- Documented severe gastroparesis
- Active intestinal obstruction
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 |
|---|---|---|
| MITI-001 administrationA complex gut bacterial community (MITI-001) will be given endoscopically and orally | Drug | Intervention arm (MITI-001) |
Primary outcome
Determine the safety of MITI-001 in the participant population
Time frame: up to 90 days
Incidence of MITI-001-related adverse events
2 secondary outcomes
Assess the ability of MITI-001 to restore microbial metabolic function: secondary bile acid metabolism and hydrogen consumption
Time frame: Day 30 and Day 90
Adequate relief of IBS-D symptoms
Time frame: Day 30
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 20 Nov 2025.
- Individual participant dataSharing planned: No
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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.
Clinical Research Coordinator contact
Michael Fischbach, PhD study director
Stanford University
Sean P Spencer, MD, PhD principal investigator
Stanford University
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing MITI-001 administration in people with IBS (Irritable Bowel Syndrome) and Diarrhea, run by Stanford University at 2 sites 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 12 inclusion and 22 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: opening soon, as of the sponsor's last update on 20 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
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 Sean Assistant Professor of Medicine (6507365555, seanspen@stanford.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Determine the safety of MITI-001 in the participant population (time frame: up to 90 days). 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 20 Nov 2025.