Efficacy, safety, and tolerability of fructooligosaccharides in the treatment of irritable bowel syndrome.

BACKGROUND: Interest in fructooligosaccharides as a health-promoting food component is increasing. Fructooligosaccharides are mainly indigestible and large amounts in the colon may provoke gastrointestinal symptoms. OBJECTIVE: The symptoms of irritable bowel syndrome (IBS) may be provoked by large quantities of carbohydrates in the colon. The objective of this study was to determine whether regular consumption of fructooligosaccharides worsens gastrointestinal symptoms in patients with IBS. DESIGN: A multicenter, prospective, randomized, double-blind, placebo-controlled parallel group comparison was conducted at 24 sites. The study consisted of a 2-wk, single-blind run-in phase and a 12-wk, double-blind comparative phase. Subjects were randomly assigned to receive 20 g fructooligosaccharides powder/d (n = 52) or a placebo (n = 46). Efficacy was based on the patients' overall response to treatment at completion of the study and on the severity and duration of individual symptoms (abdominal distension, abdominal rumbling, abnormal flatulence, and abdominal pain). RESULTS: Data from 96 patients (16 men and 80 women) were analyzed. After 4-6 wk of treatment, IBS symptoms improved more in the placebo group than in the fructooligosaccharide group. After completion of the study, there were no significant differences between the 2 groups: symptoms improved in 58% of the fructooligosaccharide group and in 65% of the placebo group and symptoms worsened in 8% of the fructooligosaccharide group and in 13% of the placebo group. CONCLUSION: Although symptoms worsened in patients with IBS at the onset of treatment with 20 g fructooligosaccharides/d, continuous treatment for 12 wk resulted in no worsening of symptoms.