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The Stool Microbiome of Treated and Untreated IBS (Irritable Bowel Syndrome) Patients

Generating a Stool Microbiome-based Diagnostic for IBS (Irritable Bowel Syndrome) Patients in Low-FODMAP Treated and Untreated IBS Patients

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05972317
Enrollment
100
Registered
2023-08-02
Start date
2026-05-11
Completion date
2029-11-01
Last updated
2026-06-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Irritable Bowel Syndrome

Brief summary

Irritable bowel syndrome (IBS) is considered the most common gastrointestinal disorder in humans, with an estimated global prevalence of 11%-20% of all humans. Alterations in the gut microbiome are at the center of IBS, and microbiome-induced volatile metabolites in response to dietary exposures is believed to drive a downstream impact on susceptible hosts, thereby driving the disease. However, the characteristics and functions of these metabolites remain unknown to date. The two main mechanisms invoking IBS development and flares include 1) an increase in luminal water content due to malabsorption of small molecules and 2) incrementation of colon gas production generated by the fermentation of small molecules by gut bacteria.Yet to date, a person-specific elucidation of the specific small molecules and bacteria driving IBS, and their downstream effects on the human gut epithelium remain unknown. Over the past years, it became evident that dietary regimes, and their interactions with the intestinal microbiome, are at the center of IBS symptom generation and alleviation. The most widely used dietary intervention is a highly restrictive diet, the low-Fermentable Oligo-saccharides Di-saccharides Mono-saccharides And Polyols (FODMAP) diet, based on avoidance of multiple food items that contain available fermentable molecules. The low-FODMAP diet remains an effective line of treatment for IBS patients, yet due to its complexity and unhealthy nature, it remains a last line of treatment and fails to impact the majority of IBS patients.

Interventions

OTHERLow FODMAP dietary regimen

intervention will include a guidance by a clinical dietitian about low FODMAP diet The FODMAP diet has three phases: 1. Elimination - Avoidance from high-FODMAP foods (2-6 weeks) 2. Reintroduction -Structured challenges of specific food groups each time (6-8 weeks). 3. Maintenance - personalized diet, according to the response in step 2.

Sponsors

Weizmann Institute of Science
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes

Inclusion criteria

* Male and Female * Age - 18-70

Exclusion criteria

* Consumption of antibiotics 2 months prior to the first day of the experiment. * Consumption of probiotic supplements 1 month prior to the first day of the experiment. * Type 1 or type 2 diabetes diagnosis. * Pregnancy, fertility treatments, breastfeeding 3 months prior to the first day of the study. * Chronic disease - to the discretion of the study doctor. * Cancer and recent anticancer treatment. * Psychiatric disorders - to the discretion of the study doctor. * IBD (inflammatory bowel diseases). * Alcohol or substance abuse. * BMI \> 35.

Design outcomes

Primary

MeasureTime frameDescription
IBS-SSS - irritable bowel syndrome severity score system questionnaire1 weekSeverity of symptoms as they are scored in the Rome IV IBS-SSS 75 to \<175 to indicate mild IBS, 175 to \<300 as moderate, and \>300 as severe
IBS-QOL questionnaire - irritable bowel syndrome quality of life questionnaire1 weekQuality of life scores from the Rome IV IBS-QOL 0-100 scale for ease of interpretation with higher scores indicating better IBS specific quality of life

Secondary

MeasureTime frameDescription
Stool microbiome differences between the study arms - using fecal samples of participants3 monthsAnalysis of stool samples of the different study arms - using shot-gun metagenomics to asses type of microbiota pre and post low-FODMAP diet.

Countries

Israel

Contacts

CONTACTYotam Cohen
Yotam.cohen@weizmann.ac.il+97289529173
CONTACTShimrit Eliyahu Miller
shimrit.miller@weizmann.ac.il
PRINCIPAL_INVESTIGATOREran Elinav, Prof

Weizmann Institute of Science

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 12, 2026