Effect of scFOS on Increase in Stool Frequency in Constipated People

Inclusion Criteria: * functional constipation according to ROME III criteria with 3 or less than 3 stools per week * BMI between 18 and 32kg/m², limits included * Subjects who do not usually eat high-fibre foods * Subjects who do not usually consume foods siad "reduced in sugars" or "light" * Subjects who do not consume regularly pre- and probiotics in the form of dietary supplements Exclusion Criteria: * subjects presenting Irritable bowel syndrome * history of chronic GI disorders: crohn disease, ulcerative colitis,.... * treatments likely to influence GI sensitivity or motility (laxative, neuroleptics,...) * Antibiotic therapy in progress or in the past 8 weeks * medical history with impact on the study objectives as defined by investigator * known food allergy to one of the compounds of the study product