Investigating fructose absorption variability within a healthy New Zealand adult population

Abstract

Background: Fructose is a simple sugar and fermentable carbohydrate consumed naturally in the diet. Unlike glucose, fructose absorption capability varies between individuals, with unabsorbed fructose potentially causing gastrointestinal distress. A by-product of fructose malabsorption is hydrogen. Hydrogen breath testing is a non-invasive method utilised to test for fructose malabsorption, and could be used to screen for fructose malabsorption prior to the commencement of elimination diets such as the low FODMAP approach, commonly used to help manage Irritable Bowel Syndrome (IBS). Aim: To primarily investigate the variability in fructose absorption in a healthy New Zealand adult population and secondly to characterise the relationships between fructose absorption, incidence of Irritable Bowel Syndrome, dietary intake of short-chain fermentable carbohydrates, age and gender. Methods: Eighty participants completed a single two-hour hydrogen-breath testing session following the ingestion of a 35g fructose solution. Fifteen participants failed to complete all aspects of the trial and were excluded. Participants provided breath samples at baseline, 30, 60 and 120 minutes. Irritable Bowel Syndrome (IBS) was screened for as part of the health questionnaire, using the validated ROME IV questions and dietary data collected via the Monash Comprehensive Nutrition Questionnaire. The data were analysed using the following non-parametric methods; Mann-Whitney, Kruskal-Wallis and Spearman r correlations, statistical significance was set as p <0.05. Results and Discussion: The sample cohort was comprised of 63 females and 17 males, with an average age of 24. Over half (57%) of participants were able to absorb the 35g fructose solution. No significant differences or trends were absorbed between fructose absorption status (absorbers vs non-absorbers) and dietary fructose and short-chain fermentable carbohydrates, irritable bowel syndrome, age or gender. A number of future research suggestions are made surrounding the utilisation of hydrogen breath testing for the investigation of fructose malabsorption in individuals with and without IBS. Conclusion: Hydrogen breath testing proves a useful, non-invasive method of identifying fructose malabsorption in healthy individuals. The findings of this trial suggest regardless of IBS diagnosis, age, gender and dietary consumption of fructose and other fermentable short chain carbohydrates there are no significant differences between fructose absorbers and nonabsorbers. Further research across a significantly larger socio-economic cohort is required to confirm these findings.