Effectiveness of a Dietary Supplement in Irritable Bowel Syndrome (ACALMI)

February 19, 2026 updated by: University Hospital, Rouen

Irritable bowel syndrome (IBS) affects around 5% of the general population and remains a daily problem in clinicians' practices, with inconsistent efficacy of treatments despite patients' high expectations. Intestinal hyperpermeability and visceral hypersensitivity are the two major components of IBS, and both can disrupt gastrointestinal function and ultimately impair patients' quality of life.

Glutamine is a non-essential amino acid that regulates numerous metabolic pathways and plays a key role in the intestine as it is the preferred substrate for enterocytes and immune cells. A decrease in intestinal glutamine synthetase has been found in IBS, suggesting its involvement in the intestinal permeability and visceral hypersensitivity observed in patients. Ex vivo, glutamine is capable of restoring the expression of tight junction proteins in IBS-D patients. Furthermore, glutamine supplementation is capable of reducing abdominal pain and restoring intestinal permeability disorders in a sub-group of patients with intestinal permeability disorders (post-infectious IBS-D).

The marine peptides Gabolysat® produced by the Dielen Laboratory have demonstrated their efficacy on intestinal permeability and inflammation in a preclinical model of IBS (Langlois et al. 2023), similar to glutamine supplementation in these animals. The Dielen® Protect product formulated on the basis of the results of this study combines glutamine and Gabolysat® to provide a comfort solution for IBS patients.

Our working hypothesis is that patients suffering from moderate or severe IBS could benefit from oral supplementation with DIELEN Protect to improve the symptoms associated with IBS.

100 patients with IBS (according to Rome IV criteria) will be included in our study.

All patients will test the treatment for 8 weeks (dielen protect or placebo). The efficacy will be compared between the 2 groups before and after the treatments using validated questionnaires. Therefore, all participants will fill questionnaire before and after 8 weeks of treatments : IBS severity (IBS-SSS), quality of life (GIQLI), Anxiety and depression (HAD), GI symptom related anxiety (VSI), stool frequency and consistancy (BSF scale). Microbiota, metabolomic and short chain fatty acid will be analysed before and after the intervention.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Irritable bowel syndrome according to Rome IV criteria
  • Aged between 18 and 75 years
  • IBS-SSS > 175 at inclusion
  • For women of childbearing age, use of effective contraception (progestins or oestroprogestins or intrauterine device or tubal ligation) for 1 month unless postmenopausal (amenorrhoea of at least 12 months or biologically confirmed diagnosis) or woman who has had a hysterectomy or salpingectomy.
  • Irritable bowel syndrome treatments that have been stable for more than one month
  • Membership of a social security scheme
  • Patient has read and understood the information letter and signed the consent form

Exclusion Criteria:

  • Taking probiotics, food supplements containing glutamine, anti-inflammatory drugs or antibiotics in the month preceding the study.
  • Allergy to fish and glutamine
  • Known renal insufficiency (Glomerular Filtration Rate (GFR)<30mL/min/1.73m2), known hepatic insufficiency (Prothrombin Time (PT)<70%) or known cardiac disease.
  • History of organic digestive disease (coeliac disease, inflammatory bowel disease, abdominal surgery other than appendectomy or cholecystectomy)
  • Pregnant women, women in labour or breastfeeding mothers
  • Person deprived of liberty by an administrative or judicial decision or person placed under court protection / sub-guardianship or guardianship
  • Patient taking part in another trial / having taken part in another trial within a 4-week period

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: treatment with DIELEN® Protect
experimental group: treatment with DIELEN® Protect for 8 weeks at a dose of 5 grams, 3x a day
Drug: treatment with DIELEN® Protect
treatment with DIELEN® Protect for 8 weeks at a dose of 5 grams, 3x a day
Other Names:
  • Dielen
Placebo Comparator: control group
Control group: treatment with placebo (pea protein) for 8 weeks at a dose of 5 grams, 3x a day
Drug: treatment with placebo of DIELEN® Protect
treatment with placebo of DIELEN® Protect for 8 weeks at a dose of 5 grams, 3x a day
Other Names:
  • placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Symptomatic efficacy of DIELEN® Protect supplementation
Time Frame: from enrollment up to 8 weeks
change in IBS severity score (IBS-SSS) measured before and after 8 weeks of DIELEN® Protect or placebo supplementation in patients The IBS-SSS is a questionnaire used to assess the severity of irritable bowel syndrome. Rated from 0 to 50, 50 is the worst case with a severe case
from enrollment up to 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
impact of DIELEN® Protect on the composition of the intestinal microbiota
Time Frame: from enrollment up to 8 weeks
variation in the composition of faecal microbiota measured before and after supplementation with DIELEN® Protect or placebo for 8 weeks.
from enrollment up to 8 weeks
Impact of DIELEN® Protect on quality of life
Time Frame: from enrollment up to 8 weeks
change in GIQLI score measured before and after 8 weeks' supplementation with DIELEN® Protect or placebo GILQLI : self-administered questionnaire completed by the patient, comprising 36 questions relating to digestive symptoms, their social and emotional impact, and general condition over the last few days. The answer to each question is scored from 0 (permanent symptoms) to 4 (no symptoms). The individual score is calculated by adding up all the points obtained for all the items. The overall score varies from 0 (worst possible quality of life) to 144 (best possible quality of life).
from enrollment up to 8 weeks
impact of DIELEN® Protect on gastrointestinal related anxiety
Time Frame: from enrollment up yto 8 weeks

change in VSI score measured before and after DIELEN® Protect or placebo supplementation for 8 weeks

VSI : 'gastrointestinal related anxiety' scale. This scale is based on 15 questions, all with answers ranging from 0 to 5. At the end of the questionnaire, a score out of 75 is obtained. Scores close to 0 indicate no gastrointestinal anxiety, while scores close to 75 indicate severe gastrointestinal anxiety.
from enrollment up yto 8 weeks
impact of DIELEN® Protect on anxiety and/or depression
Time Frame: from enrollment up to 8 weeks

variation in HAD score measured before and after 8 weeks' supplementation with DIELEN® Protect or placebo

The HAD scale detects the presence of anxiety or depression. Each symptom is scored on 21 points. A score below 8 eliminates anxiety or depression, a score between 8 and 10 defines a doubtful state of anxiety or depression, and a score above 10 a definite state of anxiety or depression.
from enrollment up to 8 weeks
impact of DIELEN® Protect on stool frequency
Time Frame: from enrollment up to 8 weeks
variation in the mean number of stools per day before and after 8 weeks' supplementation with DIELEN® Protect or placebo (stool calendar)
from enrollment up to 8 weeks
impact of DIELEN® Protect on stool consistency
Time Frame: from enrollment up to 8 weeks

variation in the Bristol stool form before and after 8 weeks' supplementation with DIELEN® Protect or placebo

the Bristol stool form (Score de Bristol) class stools in 7 types from type 1 = constipation to type 7 = diarrhoea
from enrollment up to 8 weeks
treatment compliance rate
Time Frame: from enrollment up tu 8 weeks
Compliance will be assessed by measuring the number of sachets of DIELEN® Protect or placebo not taken after 8 weeks of treatment. The patient will be considered non-compliant if the uptake of DIELEN® Protect or placebo over the 8 weeks is < 70%.
from enrollment up tu 8 weeks
Number and severity of adverse reactions
Time Frame: from enrollment up to 8 weeks
Tolerance will be assessed by the number and severity of adverse reactions at the end of treatment.
from enrollment up to 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Rouen

Collaborators

Laboratoire Dielen

Investigators

  • Principal Investigator: Chloé MELCHIOR, PUPH, University Hospital, Rouen

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 22, 2025

Primary Completion (Estimated)

February 1, 2027

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

June 18, 2025

First Submitted That Met QC Criteria

June 18, 2025

First Posted (Actual)

June 26, 2025

Study Record Updates

Last Update Posted (Actual)

February 23, 2026

Last Update Submitted That Met QC Criteria

February 19, 2026

Last Verified

June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024/0178/HP

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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