Efficacy of a Low FODMAP Diet According to Colonic pH in Irritable Bowel Syndrome Patients (FOSIIL)

Efficacy of a Low FODMAP Diet According to Colonic pH Measured by Wireless Motility Capsule in Irritable Bowel Syndrome Patients

Treatments efficacy in irritable bowel syndrome (IBS) patients is inconstant and predictive factors of their efficacy are needed. The role of dysbiosis in IBS is well-known. Another way to identify microbiota differences is to assess its metabolic activity. It has been demonstrated that colonic pH in IBS patients is lower than in healthy volunteers, reflecting a highest colonic fermentation. Colonic acidification is able to sensitize colonic mechano-receptors to distension. Microbiota profile is able to predict the response to a low Fermentable Oligo, Di, Monosaccharides And Polyols (FODMAPs) diet, but is not available in clinical routine.

The aim of our study is to assess the link between colonic fermentation (measured by colonic pH) and the efficacy of a low FODMAPs diet in IBS patients (measured by IBS severity scoring system (IBS-SSS)). We hypothesis that IBS patients with a lower colonic pH will have a better efficacy of the low FODMAPs diet. It might allow in the future personalized medicine.

50 IBS patients according to Rome IV criteria will be included in our study. All patients will have a measure of their colonic pH by wireless motility capsule. Patients will follow a low FODMAPs diet for 6 weeks after an education by a trained dietician. All participants will fill validated questionnaires before and after 6 weeks of low FODMAPs diet: IBS-SSS, Gastro Intestinal Quality of Life Index (GIQLI), Hospital Anxiety and Depression (HAD) scale. Microbiota, metabolomic and short chain fatty acid will be analysed before and after the intervention. The number of patients was calculated to assess the correlation between colonic pH and the variation of IBS-SSS before and after the intervention.

Study Overview

• Status: Terminated
• Conditions: Irritable Bowel Syndrome
• Intervention / Treatment: Dietary supplement: Low FODMAP diet

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Rouen, France, 76000
    • Rouen University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 76 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• IBS according to Rome IV criteria
• Normal blood test (cell blood count, C Reactive Protein, thyroid-stimulating hormone, anti transglutaminase antibodies) in the last 12 months
• IBS severity score (IBS-SSS) >175/500
• IBS treatments stable in the last month
• Effective contraception since 1 month for women in childbearing age

Exclusion Criteria:

• Anorexia nervosa or any eating disorders deemed incompatible
• Organic gastroenterological diseases (inflammatory bowel disorder, microscopic colitis, gastrointestinal cancer, celiac disease)
• Contra-indication to the wireless motility capsule (intestinal stenosis, digestive fistula or obstruction, history of bezoar, gastrointestinal surgery in the last 3 months, acute diverticulitis, cardiac pacemaker, implanted electromedical device, magnetic resonance imaging planned in the 5 days after the wireless motility capsule, swallowing disorder)
• Breastfeeding or pregnant women
• Participation in another clinical trial in the last 2 weeks
• Patient who could not stop proton pump inhibitor treatment for 10 days
• Person with administrative or judicial decision or under legal protection measure

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: IBS patients; Patients suffering from IBS according to Rome IV criteria	Dietary supplement: Low FODMAP diet; After the realisation of a wireless motility capsule, patients will underwent 6 weeks of low FODMAP diet after dietician education. Symptomatic scores (IBS-SSS, GIQLI, HAD) and stools samples (metabolomic and lipidomic) will be performed before and after the low FODMAP diet.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between efficacy of the low FODMAP diet on severity and the colonic pH	Correlation between colonic pH (baseline) and the variation of IBS severity score (IBS-SSS). IBS-SSS is a score between 0 (no symptom) to 500 (highest symptom level).	6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between efficacy of the low FODMAP diet on quality of life and the colonic pH	Correlation between colonic pH (baseline) and variation of the quality of life Index (GIQLI). GIQLI is a score between 0 (lowest quality of life) and 144 (best quality of life).	6 weeks
Correlation between efficacy of the low FODMAP diet on stool frequency and the colonic pH	Correlation between colonic pH (baseline) and variation of the stool frequency	6 weeks
Correlation between efficacy of the low FODMAP diet on stool consistency and the colonic pH	Correlation between colonic pH (baseline) and variation of the stool consistency (BSF)	6 weeks
Correlation between efficacy of the low FODMAP diet on anxiety and the colonic pH	Correlation between colonic pH (baseline) and variation of anxiety (HAD). HAD anxiety is a scale comprised between 0 (no anxiety) and 21 (highest anxiety).	6 weeks
Correlation between efficacy of the low FODMAP diet on depression and the colonic pH	Correlation between colonic pH (baseline) and variation of depression (HAD). HAD depression is a scale comprised between 0 (no depression) and 21 (highest depression).	6 weeks
Correlation between short chain fatty acids and the colonic pH	Correlation between colonic pH (baseline) and variation of short chain fatty acids (in the stool)	6 weeks
Correlation between metabolites and the colonic pH	Correlation between colonic pH (baseline) and variation of metabolites (in the stool). Among metabolites, short chain fatty acids, 28 biliary acids and lipopeptides (C12-GABA, C12-Glutamine, C14-Glutamine, C15-GABA, C16-Glutamate, C16-Glutamine, C18-GABA, C12:1-Alanine (Ala)-GABA, C12-Ala-GABA, C13-Ala-GABA, C14:1-Ala-GABA et C183OH-Glutamate-GABA) will be assessed. Metabolites will be also assessed by RMN spectroscopy that allow the assessment of a high ranges of different metabolites.	6 weeks
Colonic pH according to small intestinal bacterial overgrowth	Comparison of colonic pH between patients with and without small intestinal bacterial overgrowth	baseline
Colonic pH according to fructose malabsorption	Comparison of colonic pH between patients with and without fructose malabsorption	baseline
Colonic pH according to visceral hypersensitivity	Comparison of colonic pH between patients with and without visceral hypersensitivity	Baseline
Colonic pH and fecal calprotectin	Correlation between colonic pH and fecal calprotectin	Baseline
Colonic pH and rectal pain threshold	Correlation between colonic pH and rectal pain threshold	Baseline
Correlation between baseline QOL and the colonic pH	Correlation between colonic pH and baseline GIQLI (quality of life Index)	Baseline
Correlation between baseline IBS severity score and colonic pH	Correlation between colonic pH and baseline IBS severity score (IBS-SSS)	Baseline
Correlation between baseline anxiety and colonic pH	Correlation between colonic pH and baseline anxiety (HAD)	Baseline
Correlation between baseline depression and colonic pH	Correlation between colonic pH and baseline depression (HAD)	Baseline
Correlation between baseline stool consistency and colonic pH	Correlation between baseline stool consistency (BSF) and colonic pH	Baseline
Correlation between baseline stool frequency and colonic pH	Correlation between baseline stool frequency and colonic pH	Baseline

Collaborators and Investigators

• Sponsor: University Hospital, Rouen
• Investigators: Principal Investigator: Chloé Melchior, MD, PhD, University Hospital, Rouen

Study record dates

Study Major Dates

• Study Start (Actual): April 19, 2023
• Primary Completion (Actual): February 15, 2024
• Study Completion (Actual): February 15, 2024

Study Registration Dates

• First Submitted: December 8, 2021
• First Submitted That Met QC Criteria: April 6, 2022
• First Posted (Actual): April 13, 2022

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 12, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: predictive factor; Low FODMAP diet; colonic pH
• Additional Relevant MeSH Terms: Pathologic Processes; Intestinal Diseases; Disease; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Colonic Diseases, Functional; Irritable Bowel Syndrome; Syndrome
• Other Study ID Numbers: 2019/0332/HP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: upon request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No