NUTRIOSE is a food ingredient defined as a carbohydrate polymer of vegetable origin (wheat starch or corn) with a degree of polymerization ≥ 3 and chemically transformed. It is soluble in aqueous solution, very poorly digested in the small intestine, it mostly reaches the colon where it stimulates fermentation. AFSSA, in its opinion of July 30, 2007, considers that this ingredient is a "soluble dietary fiber." The objective of this research is to determine, among healthy subjects, the effect of this dietary fiber on changes in gut microbiota and digestive tolerance during a 28 days consumption. Microbiological analyzes will be performed by RT-PCR. Digestive tolerance will be measured by the intelligence of a questionnaire by volunteers.

Inclusion Criteria:

• aged 20 to 50 years,
• BMI 18 to 25 kg/m2,
• absence of known or scalable organic or psychiatric disease
• no history of chronic gastrointestinal disease
• having a bowel regularity (1-3 defecation per day, of normal consistency),
• person without medication during the study (especially laxatives, anti diarrheal) (except contraceptives in women)
• having normal laboratory hepatic and renal tests (ASAT, ALAT, GGT, urea, creatinine)
• no pregnant nor nursing women
• covered by Social Security
• negative serology for hepatitis B/C and HIV
• who signed the informed consent form

Exclusion Criteria:

• persons abusing drugs (laxatives, anti-diarrheal)
• person who doesn't want to stop taking food supplements containing pre- or probiotics during time of the study
• person intolerant to gluten and / or allergic to wheat flour
• person in vegetarian or vegan diet
• Inclusion in another clinical study
• subjects receiving over 4,500 Euros in the last 12 months (including the present study)
• subjects presenting risk of non-compliance in the opinion of the recruiting doctor.