Too Much Inulin Linked to GI Distress

ST. PAUL, Minn.Inulin, a popular carbohydrate fiber used in many processed foods, can cause gastrointestinal (GI) distress in individuals who consume too much of it, according to a new study published in the Journal of the American Dietetic Association.

During a randomized, double-blind, controlled, crossover study, researchers at the University of sought to determine the GI tolerance of two inulin fibersshorter chain length oligofructose and native inulinat 5- and 10-g doses compared to a placebo. Twenty-six healthy men and women ages 18 to 60 years participated in the study that included a phone screening and five visits for breakfast fiber challenges consisting of a bagel, cream cheese and orange juice. Healthy subjects with no history of GI conditions consumed diets with typical amounts of fiber.

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.

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.

The researchers concluded that doses up to 10 g/day of native inulin and up to 5 g/day of oligofructose were well-tolerated in healthy, young adults.