Observational Cross-Sectional Study of Intestinal Permeability in Adults With Lactose Intolerance
| Registry | NCT07424898, acronym LI |
|---|---|
| Status | Enrolling by invitation |
| Study type | Observational |
| Enrollment | 200 (Estimated) |
| Sponsor | Bezmialem Vakif University (Other) |
| Conditions | Lactose Intolerance, Adult Type, Intestinal Permability, IBS (Irritable Bowel Syndrome) |
| Dates | start 2026-02-10, primary completion 2026-12-15 (estimated), completion 2027-06-15 (estimated), first posted 2026-02-20, last updated 2026-02-25 |
| Locations | 1 site in Turkey (Türkiye) |
Related Papers Related Patents Related Grants Related Experts
All trials for Lactose Intolerance, Adult Type All trials for Intestinal Permability
"This study evaluates the interplay between lactose intolerance, intestinal barrier function (zonulin), and intestinal inflammation (fecal calprotectin) in adults, aiming to clarify their independent contributions to symptom severity and quality of life."
The gastrointestinal system's barrier functions play a critical role in maintaining intestinal and overall health. Tight junction structures, regulated by zonulin, are key components of this barrier, and elevated zonulin levels can increase intestinal permeability, facilitating translocation of luminal particles into the systemic circulation and promoting inflammation. Fecal zonulin-related proteins (ZRP) provide a non-invasive marker of intestinal barrier integrity.
Calprotectin, a pro-inflammatory protein complex released from neutrophils, serves as a reliable biomarker of mucosal inflammation. While typically normal in functional disorders such as irritable bowel syndrome (IBS), fecal calprotectin (FC) is significantly elevated in inflammatory bowel diseases (IBD), helping to distinguish organic inflammatory conditions from functional disorders.
Lactose intolerance (LI) results from lactase deficiency and is characterized by abdominal pain, bloating, and diarrhea. Traditionally attributed to mechanical and fermentative processes, recent evidence suggests that immunological and inflammatory mechanisms may also contribute. LI can be primary (genetic lactase deficiency) or secondary (due to epithelial damage or barrier dysfunction), with barrier disruption potentially exacerbating symptom severity.
Recent studies have reported elevated fecal calprotectin in individuals with self-reported milk intolerance (Seidita et al., 2023), even among those confirmed as lactose intolerant by hydrogen breath testing, suggesting that additional inflammatory or allergic mechanisms may be involved. Moreover, dietary interventions in IBS patients with food intolerances, including lactose, have been shown to significantly reduce calprotectin levels (Schnedl et al., 2023), indicating that inflammation may be modifiable.
Therefore, evaluating zonulin and calprotectin levels in lactose-intolerant adults can provide insights not only into mechanical or chemical causes of symptoms but also into intestinal barrier dysfunction and underlying inflammation. Current literature on combined assessment of these biomarkers in adults is limited. This study aims to:
Investigate the relationship between lactose intolerance and zonulin/fecal calprotectin levels.
Assess the independent contribution of zonulin (intestinal permeability) separate from calprotectin (inflammation).
Explore associations between these biomarkers, symptom severity, and quality of life.
| Arm | Type | Interventions | Description |
|---|---|---|---|
| Patients with Irritable bowel sydrome. | IBS-C, IBS-D and IBS-M. |
Sex: All, ages: 18 Years to 70 Years
Inclusion Criteria: * Adults aged 18-70 years; experiencing chronic symptoms (diarrhea, bloating, abdominal pain, constipation, flatulence) for the past 3 months, potentially fitting IBS criteria. Exclusion Criteria: \- Acute gastroenteritis (< 4 weeks), Active gastrointestinal bleeding (stomach, small intestine, and colon), Known celiac disease, Bariatric surgery or short bowel syndrome, Pregnancy or lactation, Type I and II Diabetes mellitus, Antibiotic use within the last 2 weeks, High-dose NSAIDs within the last 2 weeks, Initiation of probiotics or prebiotics within the last 4 weeks, High-dose PPI use (optional), Inflammatory bowel disease (IBD; ulceretive colitis and Crohn's colitis) with active severe flare (excluded from primary analyses, evaluated separately in subgroup analyses)
| Facility | City | Country | Status |
|---|---|---|---|
| Bezmialem Vakıf University Medical Faculty Hospital | Istanbul | Turkey (Türkiye) |