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NCT Number: NCT07039747

Effectiveness of a Dietary Supplement in Irritable Bowel Syndrome

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.

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Key information

Conditions

Irritable Bowel Syndrome Colonic Diseases Colonic Diseases, Functional Digestive System Diseases Gastrointestinal Diseases Intestinal Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

treatment with DIELEN® Protect

Drug

treatment with DIELEN® Protect for 8 weeks at a dose of 5 grams, 3x a day

Other names: Dielen

treatment with placebo of DIELEN® Protect

Drug

treatment with placebo of DIELEN® Protect for 8 weeks at a dose of 5 grams, 3x a day

Other names: placebo

Primary outcomes

  1. 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

Secondary outcomes

  1. 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.

  2. 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).

  3. 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.

  4. 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.

  5. 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)

  6. 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

  7. 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%.

  8. 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.

Study contacts

Contact information is provided by the study sponsor or research team.

Chloé MELCHIOR, PUPH

CONTACT

[email protected]

00332 32 88 67 07

Mylene HERVET

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

University Hospital, Rouen

Other

Collaborators

  • Laboratoire Dielen

Registry information

Acronym: ACALMI

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Jun 26, 2025
Registry last updated
Feb 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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