A Longitudinal Study to Identify IBS Phenotypes Using Fecal Microbiota and Hydrogen Breath Testing

NCT ID: NCT03219528

Last Updated: 2025-04-27

Study Results

Results available

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE4

Total Enrollment

74 participants

Study Classification

INTERVENTIONAL

Study Start Date

2018-02-13

Study Completion Date

2024-02-28

Brief Summary

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Diarrhea-predominant irritable bowel syndrome (IBS-D) is a highly prevalent but poorly understood condition with limited treatment options. Current therapies, including a nonabsorbable antibiotic rifaximin or diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), show efficacy in 50% or less of patients. In this proposal, participants with IBS-D will be randomized to receive either rifaximin or low FODMAP dietary intervention.

Detailed Description

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Diarrhea-predominant irritable bowel syndrome (IBS-D) is a highly prevalent but poorly understood condition with limited treatment options. Recent evidence has established small intestinal bacterial overgrowth (SIBO) and alterations in fecal microbiota as potential etiologies in the pathogenesis of IBS-D. Current therapies, including a nonabsorbable antibiotic rifaximin or diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), show efficacy in 50% or less of patients \[1-4\]. It has been postulated that limited responses to therapies may stem from failure to identify distinct subgroups in IBS-D stratified by gut microbial profiles. In this proposal, participants with IBS-D will be randomized to receive either rifaximin or low FODMAP dietary intervention. The results of fecal microbiota-derived data as well as hydrogen breath tests will then be longitudinally followed to define SIBO. These methods will be used to test the hypotheses that: (i) distinct IBS-D phenotypes can be generated by defining fecal microbial populations as well as delineating the presence or absence of SIBO; and (ii) longitudinal analyses using microbe-derived metrics and SIBO status may relate to response to treatment with rifaximin or low FODMAP dietary intervention.

Conditions

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Irritable Bowel Syndrome

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Rifaximin

Rifaximin 550 mg three times daily for 14 days

Group Type ACTIVE_COMPARATOR

Rifaximin 550 MG

Intervention Type DRUG

Rifaximin 550 mg three times daily for 14 days

Low FODMAP Group

Low FODMAP diet for 4 weeks

Group Type ACTIVE_COMPARATOR

Low FODMAP Diet

Intervention Type OTHER

Low FODMAP dietary intervention for 4 weeks

Interventions

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Rifaximin 550 MG

Rifaximin 550 mg three times daily for 14 days

Intervention Type DRUG

Low FODMAP Diet

Low FODMAP dietary intervention for 4 weeks

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

Adult subjects greater than or equal to 18 years of age who meet Rome IV criteria for diarrhea-predominant irritable bowel syndrome (IBS-D).

Prior colonoscopy or sigmoidoscopy within the past 2 years with random colon biopsies to exclude the presence of microscopic colitis.

IBS medications, including anti-depressants, will be allowed if the dose has been stable for at least 1 month before inclusion. Medications will be carefully tracked to follow any potential confounding issues.

Exclusion Criteria

Underlying celiac disease, inflammatory bowel disease, or other organic disease that could explain their symptoms.

Subjects with a history of GI tract surgery, except for cholecystectomy or appendectomy, will also be excluded from the study.

Women who are pregnant or breastfeeding Antibiotics taken within 3 months prior to enrollment will not be permitted. Subjects on probiotics must discontinue their use at least 1 month prior to enrollment.

Subjects who have previously received formal dietary education for IBS, including a low FODMAP diet, or previously received antibiotics, including rifaximin, for treatment of IBS-D will be excluded from the study.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Michigan Institute for Clinical and Health Research (MICHR)

UNKNOWN

Sponsor Role collaborator

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role collaborator

University of Michigan

OTHER

Sponsor Role lead

Responsible Party

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Allen Lee

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Allen Lee, MD

Role: PRINCIPAL_INVESTIGATOR

University of Michigan

Locations

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University of Michigan

Ann Arbor, Michigan, United States

Site Status

Countries

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United States

Provided Documents

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Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

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1K23DK124567

Identifier Type: NIH

Identifier Source: secondary_id

View Link

HUM129427

Identifier Type: -

Identifier Source: org_study_id

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