NCT03219528

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

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 74 (actual)
• Sponsor: University of Michigan · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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

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

• Irritable Bowel Syndrome

Interventions

Type	Name	Description
DRUG	Rifaximin 550 MG	Rifaximin 550 mg three times daily for 14 days
OTHER	Low FODMAP Diet	Low FODMAP dietary intervention for 4 weeks

Timeline

• Start date: 2018-02-13
• Primary completion: 2024-02-28
• Completion: 2024-02-28
• First posted: 2017-07-17
• Last updated: 2025-04-27
• Results posted: 2025-04-27

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study