Sucrase‑isomaltase genes and meal response in people with IBS

Comparison of a Meal Load Between Normal and Functional Variants of the Sucrase-isomaltase (SI) Gene in IBS

Not applicable Interventional Region Skane · NCT07309601

This research will test whether people with IBS who have reduced sucrase‑isomaltase enzyme activity have a smaller rise in blood sugar and more bowel symptoms after a sugar‑rich meal than people with normal enzyme activity.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment70 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorRegion Skane Academic / other
Locations1 site (Malmö, Skåne County)
Trial IDNCT07309601 on ClinicalTrials.gov

What this trial studies

Participants previously genotyped for sucrase‑isomaltase and other carbohydrate‑processing genes are invited for a single fasting visit. After completing symptom questionnaires, each person eats a standardized sugar‑rich meal and blood is drawn before the meal and at multiple time points up to 120 minutes to measure glucose. At the same time points they report bowel symptoms, and the team compares glucose responses and symptom changes between those with reduced enzyme activity and those with normal activity. The study will also examine correlations between blood glucose levels and symptom severity.

Who should consider this trial

Good fit: Ideal candidates are adults with an IBS diagnosis who were previously genetically tested for sucrase‑isomaltase (and related carbohydrate‑processing genes) in the listed prior studies and can attend a fasting clinic visit.

Not a fit: Patients without reduced sucrase‑isomaltase activity, or those whose symptoms are driven by conditions excluded from the study (for example celiac disease or inflammatory bowel disease), are unlikely to gain direct benefit from this specific test.

Why it matters

Potential benefit: If successful, the results could help identify people with IBS who would benefit from targeted carbohydrate‑restricted diets and more personalized dietary advice.

How similar studies have performed: Prior dietary studies of starch‑ and sucrose‑reduced diets and genetic work on SI variants have suggested links to symptoms, but direct meal‑challenge studies correlating glucose rise with immediate symptom changes are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Diagnosis of irritable bowel syndrome (IBS)
* Gene testing has been conducted regarding genes regulating the production of sucrase-isomaltase ensymes in previous dietary interventions using the starch- and sucrose reduced diet (SSRD) or multi-center study.

Exclusion Criteria:

* Diagnosis of inflammatory bowel disease, celiac disease, bile salt malabsorption, gastroenteritis or enteric dysmotility
* Severe food allergy
* Serious heart-, lung-, cardiovascular-, malignant- or mental illness
* Ongoing eating disorder
* Pregnancy
* Recent major gastrointestinal surgery
* Alcohol and/or drug addiction

Where this trial is running

Malmö, Skåne County

Study contacts

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 IBS - Irritable Bowel SyndromeSucrase-Isomaltase DeficiencyIBSSI genesStarch and sucroseblood glucose levelsbowel symptoms
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.