Date of Award


Degree Type


Degree Name

Master of Science (MS)


Nutrition and Food Sciences

First Advisor

Kathleen J. Melanson


Objective: Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) are a group of carbohydrates that evade digestion in the small intestine and are subsequently metabolized by colonic microbiota. Colonic fermentation of FODMAPs has been linked to a prebiotic effect resulting in improved blood glucose response and subjective appetite. The purpose of this study was to examine how changes in FODMAP consumption effects blood glucose response and subjective appetite. Fasting breath hydrogen was also examined as an indicator of colonic fermentation.

Design: This study utilized a single blind, randomized, crossover design. Healthy participants (n=16) were instructed to follow a low-FODMAP and high-FODMAP diet for a period of three days separated by an 11-day “washout period.” Fasting and post-prandial blood glucose were assessed via Cholestech. Subjective appetite was analyzed through use of visual analogue scales. Data were analyzed via repeated measures analysis of variance.

Results: Blood glucose concentrations did not vary significantly between the two dietary interventions (p=.111, η2 =.155). Reduced total area under the curve (TAUC) was seen after the high-FODMAP intervention, however, this decrease was not significant (6722±861 vs. 7149±1120 mg/dl*min, p=.178). No significant changes in subjective appetite were noted. Fasting breath hydrogen did not vary significantly between the two interventions, however, was found to be inversely correlated with glycemic response (r=-0.54, p=.034). Outcomes were reanalyzed utilizing only subjects consuming greater than 4 grams of FODMAPs during high-FODMAP iii intervention. Reduced post-prandial blood glucose response (F(1,7df)=7.21,p.007) and blood glucose TAUC was seen (t=3.60, p=.009) in this subset.

Conclusion: The High- FODMAP intervention resulted in a non-significant reduction in blood glucose. However, poor dietary compliance likely explains this result. The inverse relationship seen between breath hydrogen and blood glucose TAUC indicate a potential prebiotic effect. Individuals compliant with high FODMAP diet did show reduced glycemic response. Further research, with larger samples and longer interventions, is needed.