Use of A Complex Gut Bacterial Consortium (MITI 001) for the Treatment of Irritable Bowel Syndrome With Diarrhea

NCT07238790 | Not Yet Recruiting Early Phase 1 FDA Drug

• 2 other identifiers: 8227731936
• Study Type: interventional
• Target: 13
• Locations: 1 country
• Sites: 2

Brief 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 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.

Conditions

IBS (Irritable Bowel Syndrome); Diarrhea

Keywords

IBS with Diarrhea Predominance (IBS-D)

Outcome Measures

Primary Outcomes (1)

• Determine the safety of MITI-001 in the participant population

  Incidence of MITI-001-related adverse events

  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

  Day 30 and Day 90

• Adequate relief of IBS-D symptoms

  Day 30

Other Outcomes (3)

• Determine whether restoration of microbial metabolic function leads to a reduction in IBS symptom burden in participants

  up to 90 days

• Measure the extent of engraftment at the taxonomic and cellular level

  one week after last dose of MITI-001

• Measure the durability of engraftment and community stability over time

  90 days

Study Arms (1)

Intervention arm (MITI-001)

EXPERIMENTAL

Dosed with MITI-001

Drug: MITI-001 administration

Interventions

MITI-001 administration DRUG

A complex gut bacterial community (MITI-001) will be given endoscopically and orally

Intervention arm (MITI-001)

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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
• 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.

You may not qualify if:

• 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)
• 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

Sponsors & Collaborators

• Stanford University: lead

Study Sites (2)

Stanford Digestive Health Clinic

Redwood City, California, 94063, United States

Location

Stanford University

Stanford, California, 94305, United States

Location

MeSH Terms

Conditions

Irritable Bowel Syndrome; Diarrhea

Condition Hierarchy (Ancestors)

Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Signs and Symptoms, Digestive; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Michael Fischbach, PhD

  Stanford University

  STUDY DIRECTOR

• Sean P Spencer, MD, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Sean Assistant Professor of Medicine

CONTACT

6507365555; seanspen@stanford.edu

Clinical Research Coordinator

CONTACT

aadiao@stanford.edu

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Medicine

Study Record Dates

• First Submitted: November 16, 2025
• First Posted: November 20, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): December 1, 2030
• Last Updated: November 20, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)