Glutamine to improve the gut lining in people with diarrhea-predominant IBS and increased intestinal permeability

Efficacy of Glutamine Supplementation in Patients Suffering From Irritable Bowel

Not applicable Interventional University Hospital, Rouen · NCT06291038

This trial will test whether taking oral glutamine helps adults with diarrhea-predominant IBS who have increased intestinal permeability.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorUniversity Hospital, Rouen Academic / other
Locations4 sites (Amiens and 3 other locations)
Trial IDNCT06291038 on ClinicalTrials.gov

What this trial studies

Adults with IBS-D and documented increased intestinal permeability (measured by the lactulose/mannitol test) are enrolled and receive either glutamine 5 g three times daily or a protein powder placebo 5 g three times daily for eight weeks. The trial compares symptom measures (including abdominal pain and overall IBS severity) and changes in intestinal permeability before and after treatment. Eligible participants are 18–75 years old with moderate to severe IBS-D (Francis score greater than 175) and stable IBS treatments for at least one month. Concomitant recent use of probiotics, systemic antibiotics, corticosteroids or anti-inflammatories and certain active autoimmune diagnoses are exclusion criteria.

Who should consider this trial

Good fit: Adults aged 18–75 with diarrhea-predominant IBS by Rome IV, a Francis score over 175, stable IBS treatments, and documented increased intestinal permeability on the lactulose/mannitol test are ideal candidates.

Not a fit: Patients without increased intestinal permeability (for example IBS without permeability abnormalities or other IBS subtypes), those taking excluded medications, or those with excluded active autoimmune conditions are unlikely to benefit from this intervention.

Why it matters

Potential benefit: If successful, oral glutamine could reduce abdominal pain and help restore normal intestinal barrier function in a subset of IBS-D patients with permeability defects.

How similar studies have performed: Preclinical and small clinical observations show glutamine can restore tight junction proteins ex vivo and has reduced pain and corrected permeability in a subgroup of post-infectious IBS-D patients, so evidence is promising but limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult aged 18 to 75
* Diarrheal irritable bowel syndrome (IBS-D), according to the Rome IV criteria (appendix 2)
* Francis score \> 175/500 at inclusion (corresponding to moderate to severe IBS)
* Treatments for IBS stable for \>1 month
* Affiliation to a social security system
* Adult person having read and understood the information letter and signed the consent form
* Woman of childbearing age having effective/very effective contraception (Cf. CTFG) (estrogen-progestins or intrauterine device or tubal ligation) for 1 month and a negative urine pregnancy test
* Postmenopausal woman: confirmatory diagnosis (amenorrhea not medically induced for at least 12 months before the inclusion visit or biologically documented)

Exclusion Criteria:

* Taking probiotics, anti-inflammatories, corticosteroids or antibiotics systemically (oral or injectable) in the month preceding the study and during the duration of the study treatment,
* Known diagnosis of active autoimmune disease (type 1 diabetes, lupus, multiple sclerosis, thyroiditis, ankylosing spondylitis, rheumatoid arthritis or psoriasis)
* Known allergy to glutamine,
* Contraindication to taking glutamine, protein powder, lactulose or mannitol (including sugar-free chewing gum),
* Use of osmotic laxatives and/or taking lactulose and/or protein supplementation (including taking glutamine) in the 4 weeks preceding the start of the study,
* Renal insufficiency (GFR\<40mL/min), hepatic insufficiency (PT\<70) or known heart disease,
* ATCD of digestive disease (celiac disease, chronic inflammatory bowel disease, abdominal surgery other than appendectomy or cholecystectomy),
* Occlusive or subocclusive syndrome,
* Digestive perforation or suspicion of perforation,
* Abdominal pain syndrome of undetermined cause,
* Chronic alcohol consumption (\>14 units/week),
* Pregnant or parturient or breastfeeding woman or proven absence of contraception,
* Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection/under guardianship or curatorship,
* Person participating in research participating in another trial / having participated in another trial within 2 weeks,
* History of illness or psychological or sensory abnormality likely to prevent the subject from fully understanding the conditions required for participation in the protocol or preventing them from giving informed consent.

Where this trial is running

Amiens and 3 other locations

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Irritable Bowel Syndrome
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.