Which Short-Chain Carbs Are the Villains in IBS?

Malabsorption of fructose and other short-chain carbohydrates is thought to produce symptoms of irritable bowel syndrome (IBS). Common dietary sources of fructose include fruits, honey, and high-fructose corn syrup. Some carbohydrates, such as fructo-oligosaccharides (fructans) and galactosaccharides (e.g., raffinose), cannot be absorbed by humans.

Now, in a double-blind, randomized, crossover trial, researchers have assessed the effects of fructose and fructans (alone or in combination) as dietary triggers of IBS symptoms. Twenty-five patients with known fructose malabsorption were challenged by graded-dose introduction of fructose, fructans, the combination, or a glucose control administered as drinks with meals for a 2-week test period, f…