Subjects with gas-related complaints exhibit impaired handling of intestinal gas loads and we hypothesized that inulin would have a beneficial effect. Aim: to determine the effect of a prebiotic chicory-derived inulin-type fructan on the tolerance of intestinal gas. Methods. Placebo-controlled, parallel, randomized and double-blind trial study. Subjects with abdominal symptoms and reduced tolerance of intestinal gas (selected by a pre-test) will receive either inulin (8 g/d, n=18) or maltodextrin as a placebo (8 g/d, n=18) for 4 wk. A gas challenge test (4 h jejunal gas infusion at 12 mL/min while measuring abdominal symptoms and gas retention for 3 h) will be performed before and at the end of the intervention phase. Gastrointestinal symptoms and bowel habits (using daily questionnaires for 1 wk) and fecal bifidobacteria counts will be measured before and at the end of the intervention.

Inclusion Criteria:

• negative sensation of digestive well-being (score ≤ 1 on at least 2 of the 6 evaluation days, scored on a - 5 / +5 scale.
• poor tolerance of a gas challenge test (abdominal perception score ≥ 3, on a 0-6 scale, for at least three 15-min time points over the last 90 minutes of the 180-minute-long intestinal gas infusion test).

Exclusion Criteria:

• antibiotic intake,
• exceptional diets,
• changes in dietary habits or intake of Ca supplements over the preceding month.