Background: The use of inulin in foods as a fiber source has increased recently. Consumption of inulin products can cause gastrointestinal (GI) distress. Acceptable intakes of inulin need to be determined.
Objective: To determine the GI tolerance of two inulin fibers, shorter chain length oligofructose and native inulin, at 5- and 10-g doses compared to a placebo.
Design: A randomized, double-blind, controlled, crossover design that included a phone screening and five visits for breakfast fiber challenges consisting of a bagel, cream cheese, and orange juice.
Subjects/setting: Twenty-six healthy men and women ages 18 to 60 years participated in the study. Healthy subjects with no history of GI conditions consumed diets with typical amounts of fiber.
Main outcome measures: GI tolerance was calculated as the sum of scores on seven GI tolerance domains via questionnaire administered at t=0, 2, 4, 24, and 48 hours following fiber challenge.
Statistical analyses performed: A mixed effects linear model was used to compare the tolerance scores among the five fiber challenges.
Results: The two inulin fibers tended to increase GI symptoms mildly. Most frequently reported symptoms were flatulence followed by bloating. The 10-g dose of oligofructose substantially increased GI symptoms compared to control.
Conclusions: Doses up to 10 g/day of native inulin and up to 5 g/day of oligofructose were well-tolerated in healthy, young adults.
2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.