An Early Phase 1 interventional study of MITI-001 administration in IBS (Irritable Bowel Syndrome) and Diarrhea, sponsored by Stanford University. Not yet recruiting at 2 sites in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-11-20.
Sponsored by Stanford University · Early Phase 1, Interventional, and Treatment
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.
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.
1,116 studies on the registry are indexed under Irritable Bowel Syndrome; 208 are open to participants now.
This study's planned enrollment of 13 is below the median of 70 across 896 interventional studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →Stanford University is the lead sponsor of 2,168 studies on the registry; 431 are open to participants now.
Of its 267 completed or terminated interventional studies of FDA-regulated products, 207 (78%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
At least 1 of the following measures of microbiome dysfunction:
Willing to use appropriate during the treatment period and for one week after the last study visit.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dosed with MITI-001
Drug: MITI-001 administration
A complex gut bacterial community (MITI-001) will be given endoscopically and orally
Determine the safety of MITI-001 in the participant population
Incidence of MITI-001-related adverse events
Time frame: up to 90 days
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
Time frame: 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
Time frame: Day 30
Determine whether restoration of microbial metabolic function leads to a reduction in IBS symptom burden in participants
IBS symptom burden as measured by: * IBS-SSS * Rome IV Questionnaire * BSS * Abdominal Bloating and Distension Pictogram * Gastrointestinal Symptom Rating Scale * IBS-QOL Survey
Time frame: up to 90 days
Measure the extent of engraftment at the taxonomic and cellular level
Percent of participants showing engraftment of \> 30 strains from MITI-001 measured one week after the last dose of MITI-001
Time frame: one week after last dose of MITI-001
Measure the durability of engraftment and community stability over time
Percent of participants showing engraftment of \> 15 strains from MITI-001 measured 90 days after the last dose of MITI-001
Time frame: 90 days
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Dec 2025; primary completion for Dec 2028, 36 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.