Individualized targeted exclusion diet based on confocal laser endomicroscopy does not improve irritable bowel syndrome symptoms: a randomized controlled crossover trial
In brief
Targeted CLE-guided exclusion diet fails to outperform sham diet, response 42% vs 36%
In a double-blind crossover trial, IBS patients followed a diet excluding foods that triggered mucosal changes on confocal laser endomicroscopy and a sham diet excluding non-trigger foods; clinical response rates were similar (42% versus 36%). Both diets reduced symptom scores modestly, and abnormal mucosal reactions were seen in all healthy volunteers, suggesting CLE lacks predictive value for dietary therapy.
- Journal
- Gastroenterology (Q1)
- Published
- 1 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Lukas Michaja Balsiger, Jolien Schol, Karlien Raymenants, Cedric Van de Bruaene, Joran Toth, Karen Routhiaux, et al.
- PMID
- 42680074
- DOI
- 10.1053/j.gastro.2026.08.026
Why clinicians should know about it
- Picked for Pathology and Forensic Medicine (top studies of the week, 6 September 2026): Targeted exclusion diet for IBS based on CLE
- Picked for Gastroenterology (top studies of the week, 6 September 2026): Randomized crossover trial of targeted diet in IBS patients
Abstract
BACKGROUND & AIMS: In the duodenum of patients with irritable bowel syndrome (IBS), acute food-induced mucosal reactions have been visualized using confocal laser endomicroscopy (CLE). In uncontrolled studies, a diet excluding trigger foods led to symptomatic improvement. Here, we aim to assess the association of food-induced alterations identified using CLE and the efficacy of a targeted diet in a controlled study. METHODS: Double-blind, controlled, crossover study in patients with IBS. Following CLE, patients excluded up to two foods that did (= real diet) and up to two foods that did not (= sham diet) cause alterations in a randomized order. Diets were followed for four weeks each. Clinical response was defined as improving ≥50 points on the IBS symptom severity score (IBS-SSS). Healthy controls underwent the same CLE protocol as patients with IBS. RESULTS: Altered mucosa was visualized in all patients either before (11%) or after food administration. Clinical response rates were not different between real and sham diet (42% vs 36%, OR = 1.33, p = 0.6). Symptoms improved both on the real and the sham diet (-30 vs -20; p = 0.7). Also, in 15 healthy volunteers, altered mucosa was visualized in 100% of the exams either at baseline (13%) or after food administration. CONCLUSIONS: Acute alterations visualized using CLE have poor sensitivity and specificity for dietary responses in IBS patients. Moreover, altered mucosa was present in 100% of healthy volunteers and likely represents a non-specific mucosal reaction to food exposure rather than pathology, challenging the use of CLE in clinical practice to identify culprit foods. (clinicaltrials.gov: NCT05097872).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.