Is abnormal 25 g fructose breath test a predictor of symptomatic response to a low fructose diet in irritable bowel syndrome?

BACKGROUND:Fructose malabsorption may trigger gastrointestinal symptoms in irritable bowel syndrome patients and a low fructose diet seems to improve digestive symptoms. AIM:The aim of our study was to determine whether fructose malabsorption detected by a 25g fructose breath test could be a predictor of the efficacy of a low fructose diet. METHODS:88 patients (73 women, median age, 45.5 years, range 18-69) with irritable bowel syndrome according to Rome III criteria were included in this prospective, controlled study. All 88 patients had a 25 g fructose breath test; 37 had a positive test result defining fructose malabsorption. All 88 patients followed a low fructose diet for 2 weeks, blinded to their test results. Patients filled self validated-questionnaires before and at the end of the dietary period. The main outcome measurement was the Irritable Bowel Syndrome-Symptom Severity Score. RESULTS:Irritable Bowel Syndrome-Symptom Severity Score significantly decreased in fructose absorbers and fructose malabsorbers after a low fructose diet (-68.0 [-137; 0] versus -73.5 [-173; -11.5]) with no difference according to fructose breath test result (adjusted P = 0.984). CONCLUSION:A positive 25 g fructose breath test is not a predictor of the efficacy of a low fructose diet in irritable bowel syndrome. REGISTERED CLINICAL TRIAL: www.clinicaltrials.gov (NCT02188680).