An observational study in Irritable Bowel Syndrome, sponsored by Hospices Civils de Lyon. Recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-27.
Sponsored by Hospices Civils de Lyon · Observational
Irritable Bowel Syndrome (IBS), characterized by the Rome IV criteria, is a functional bowel disorder combining abdominal pain with changes in bowel habits and/or stool consistency. This condition is common, affecting 5% to 10% of the population in developed countries.
The etiology of IBS is multifactorial, involving intestinal motility disorders, visceral hypersensitivity, micro-inflammation of the intestinal mucosa, and dysbiosis. It has been demonstrated that the sub-category of IBS patients with constipation predominantly have increased amounts of Methanobrevibacter smithii, the most common methanogenic archaea found in the intestinal lumen, compared to other IBS patients.
Breath tests can evaluate methane production by the intestinal microbiota, indirectly assessing the presence and quantity of methanogenic archaea. The acronym IMO (intestinal methanogen overgrowth) defines the association of digestive symptoms (notably bloating and constipation) with a high concentration of methane in exhaled gases (≥ 10 ppm).
The links between constipation, methane production, and fecal microbiota are uncertain, necessitating further studies that could lead to precise diagnostic and treatment recommendations.
Main objective: Describe the initial composition of the fecal microbiota of constipated methano-producing IBS patients.
Secondary objectives:
2. Describe the initial composition of blood metabolites linked to the microbiota of constipated methano-producing IBS patients 3. Describe the evolution of the fecal microbiota and blood metabolites linked to the fecal microbiota during conventional therapeutic management (before and after) of constipated methano-producing IBS patients.
4. Compare the composition of the fecal microbiota before and after conventional therapeutic management of responding IBS-C patients (-30% on the IBS-SSS symptom severity score) compared to non-responding patients.
5. Evaluate the impact of Methanobrevicter smithii in the response to symptomatic treatment.
Exploratory observational single-center study (cohort follow-up) descriptive in patients with irritable bowel syndrome with constipation (IBS-C, IBS-m or IBS-U) with excessive methane production detected on a glucose breath test.
Patients will be invited to participate once the results of the breath test are known.
Please note:
In the context of this study, only two microbiota samples and 4 additional tubes and one tube of blood will be added to the usual practice. All treatments will be prescribed as part of the care and are not conditioned by the research protocol.
The primary endpoint is the analysis of the initial composition (16S rRNA gene sequencing) of the fecal microbiota of constipated methano-producing IBS patients.
The study population consists of constipated IBS patients with excessive methane production seen in the digestive functional exploration department for a breath test prescribed as part of an external procedure or a day hospital session.
A total of 40 patients will be included over 18 months, with a participation duration of 2 months +/- 2months per subject.
Patients with IBS constitute a heterogeneous population for whom only symptomatic treatment is currently offered with variable and unpredictable efficacy. Through this work, we seek to find new therapeutic axes to relieve or even treat their symptoms.
1,116 studies on the registry are indexed under Irritable Bowel Syndrome; 208 are open to participants now.
This study's planned enrollment of 40 is below the median of 160 across 191 observational studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →Hospices Civils de Lyon is the lead sponsor of 1,866 studies on the registry; 448 are open to participants now.
Counted across the registry records on this site, refreshed daily.
patients with constipation-predominant irritable bowel syndrome who are methane producers suffering from constipation, attending the digestive functional explorations department for a prescribed breath test as part of an outpatient procedure or gut health workshop session.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patient suffering from Irritable Bowel Syndrome (IBS) (abdominal pain for the past 6 months occurring on average at least 1 day per week in the last 3 months, with at least 2 of the following criteria: associated with defecation, associated with a change in stool frequency, associated with a change in stool consistency):
Exclusion Criteria:
IBS patients with constipation and methane production
Biological: Plasma Sample · Biological: Stool Sample
A peripheral venous blood sample will be collected on the day of the inclusion consultation and during the follow-up consultation at V2. These samples will be collected in a single2 tubes (4 mL and 5 mL)l tube and will be taken simultaneously with routine blood samples, which require 2 tubes (10 3 mL and 4 mLl).
Approximately 1 gram of stool will be collected by the patient at home within 72 hours following the inclusion consultation and the follow-up consultation at V2, using the kits provided along with the instructions. The stools will be immediately collected into two tubes: one tube with nucleic acid preservative and one tube conservative to ensure for future metabolomic analyses. The patient will then send the sample using the pre-paid envelope included in the kit to the HCL microbiota biobank (CRB GHN) for aliquoting and storage at -80°C.
Analysis of the initial composition (sequencing of the 16S rRNA gene) of the fecal microbiota in IBS patients with constipation and methane production.
16S rRNA gene sequencing is a molecular technique used to analyze the composition and diversity of microbial communities, such as those found in fecal samples. The 16S rRNA gene is a highly conserved region of bacterial and archaeal genomes, but it also contains hypervariable regions that can be used to distinguish between different species or strains.
Time frame: within 2 months from the first evaluation
Started Feb 2025 (actual). Primary completion is estimated for Oct 2028, 44 months after the start.
Of 51 non-industry observational studies under Irritable Bowel Syndrome, half reached primary completion within 53 months of starting (the median), counting those still running; a quarter within 28 and three quarters within 193. This study's planned 44 months is below that.
Counting every sponsor, half of 65 studies reached it within 40 months; a quarter within 21 and three quarters within 109.
How these figures are worked out, and which studies are left out of them.
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