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

Clin Nutr. 2020 Apr;39(4):1155-1160. doi: 10.1016/j.clnu.2019.04.031. Epub 2019 May 8.


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: (NCT02188680).

Keywords: Fructose breath test; Irritable bowel syndrome; Irritable bowel syndrome-symptom severity score; Low fructose diet; Predictive factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Breath Tests / methods*
  • Cohort Studies
  • Diet / methods*
  • Female
  • France
  • Fructose / metabolism*
  • Humans
  • Irritable Bowel Syndrome / metabolism*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Severity of Illness Index
  • Young Adult


  • Fructose

Associated data