Effect of Prebiotics on Intestinal Gas Production, Microbiota and Digestive Symptoms

Non-absorbable, fermentable residues in the diet increase intestinal gas production and induce gas-related symptoms, such as flatulence, abdominal bloating and distention; however, prebiotics, which are also fermented by colonic bacteria have been shown to improve this type of symptoms. The aim is to demonstrate changes in metabolic activity of gut microbiota and colonic biomass induced by prebiotics.

Healthy subjects (n=20) will be administered a prebiotic (Galacto-oligo-saccharide; 2.8 g/d) for 3 weeks; they will also receive a standard diet during three days. The following outcomes will be measured immediately before, at the beginning and at the end of the treatment: a) number of gas evacuations during daytime for 2 days on the standard diet, by means of an event marker; b) volume of gas evacuated via a rectal tube during 4 hours after a test meal, by means of a barostat; c) microbiota composition by fecal analysis.