Immune-based personalized elimination diet for the treatment of irritable bowel syndrome: a double-blind randomized sham-controlled study

Abstract Background Dietary interventions and multiple food-item restrictions are challenging for patients with irritable bowel syndrome (IBS), and associated with inadequate adherence. We aimed to examine the efficacy of an individualized-selective dietary intervention, based on Leukocyte activation to food-components (i.e. Alcat-guided diet) in IBS. Methods A randomized, double-blind, sham-controlled trial allocated IBS patients at Sheba Medical Center (Ramat Gan, Israel) between 5 August 2020 and 11 April 2022 to either an Alcat-guided or a sham-balanced diet for 8-week treatment. The primary outcome was a 50-point reduction on the IBS-symptom severity scale (IBS-SSS). The rates of improvement in the IBS Global Improvement Scale (IBS-GIS) and positive response (yes/no) were defined as secondary and exploratory outcomes, respectively. Results A total of 68 patients with IBS-D/M (44/24) were enrolled. Baseline characteristics were comparable between groups except for a higher median IBS-SSS score in the Alcat group compared with controls [390 (305–435) vs 330 (240–390), P = 0.013]. At week 8, 30 of 35 (85.7%) patients in the Alcat group met the primary outcome, compared with 18 of 33 (54.5%) of controls (P = 0.005). Alcat patients had higher rates of IBS-GIS improvement (74.3% vs 42.4%, P = 0.008) and positive response (85.7% vs 57.6%, P = 0.010) compared with controls at week 8. Among a balanced sub-cohort of patients (n = 49) with IBS-SSS score of 250–450 [median: 380 (305–410) vs 355 (310–400) for the Alcat and control groups, respectively, P = 0.487], the primary outcome was still more commonly achieved among Alcat patients compared with controls (90% vs 59%, P = 0.022). No serious adverse events were reported. Conclusion Immune-based personalized-diet was more efficient than sham-based diet for reducing symptoms in IBS patients, and may serve as a safe treatment option in this population.