It is a pilot study, conducting on 6 healthy women and aiming at defining new biomarkers related to wheat bran fermentation. For this, a breakfast, containing 5 biscuits enriched in 13-C wheat bran (which grown under 13-CO2 enriched atmosphere) is given to the subjects, then a following will be realized on 24h with breath, urine, fecal and blood samples. Analysis will be performed on these samples in order to determine potential biomarkers of fibers consumption to evaluate the metabolic effects of this consumption and to refine the relevance of nutritional recommendation regarding fibers for healthy subjects.

Inclusion Criteria:

• Subject able to understand the information given to him and having signed the informed consent form.
• subject having had a medical examination during the selection visit
• Healthy subject
• Female gender
• Age between 20 and 40 years (limits included)
• No Smoking
• Body mass index between 20 and 25 kg / m2 (limits included).
• fiber consumer ≥ 18 g / day
• Do not present any food allergy, nor food intolerance to the products of the study.
• Having no particular diet (vegetarian, vegan, high protein, etc.)
• Having a stool frequency ranging from 1 to 2 per day over the last 2 months
• Absence of pathology detectable by clinical examination and medical examination that may interfere with the evaluation criteria of the study.
• Sedentary subject or practicing steady regular physical activity during the entire study (maximum 4 hours per week).
• Accepting to submit to the protocol of the study with a day of hospitalization of 24h
• Stable weight in the last 3 months (+/- 5% of total body weight)
• Affiliation to a social security scheme.

Exclusion Criteria:

General criteria

• Subject presenting unstable medical or psychological conditions which, according to the investigator, could lead the subject to be non-compliant or uncooperative during the study or could compromise the safety or participation of the subject under study (according to Articles L.1121-6, L.1121-8, L.1121-9 and L1122-1-2 of the Public Health Code).
• Failure to respect the exclusion period of another study specified in the "National Volunteer File".
• Major subject under guardianship.
• Private subject of his liberty by judicial or administrative decision.
• Subject having exceeded the annual amount of compensation for participation in research protocols.
• Not having a refrigerator and / or freezer (necessary for the conservation of collections of urine and / or stool made at home) Biological criteria
• Total blood cholesterol> 11 mmol / L or blood triglycerides> 3 mmol / L
• Fasting blood glucose> 7 mmol / L
• CRP> 10 mg / L
• Demonstration of a biological abnormality judged by the investigator to be clinically significant
• Transaminases (ASAT and ALAT) and gamma GT greater than 1.5 times the upper limit of normal

Medical and therapeutic criteria:

• History of bariatric surgery
• History of digestive surgery with the exception of appendectomy
• Subject presenting gastrointestinal disorders such as ulcers, diverticula or inflammatory bowel diseases
• Diabetes type 1 or 2.
• Chronic renal failure.
• Chronic liver failure.
• known gastroparesis, gastrectomy, colectomy.
• History of chronic gastrointestinal disease with malabsorption.
• External pancreatic insufficiency.
• Known endocrine pathology that can interfere with carbohydrate metabolism (uncontrolled dysthyroidism, acromegaly, hypercorticism, ...).
• Subject with organic intestinal disease.
• subject who has undergone antibiotic therapy in the 3 months preceding the study may interfere with transit or intestinal microbiota:
• Subject treated with a drug that may interfere with carbohydrate metabolism:
• Corticosteroids.
• anorectics.
• High dose gastric bandages.
• Subject having a concomitant pathology incompatible with the constraints of the protocol or which may interfere with the evaluation of the main criterion.
• PA systolic not between 100 and 140 mmHg and diastolic not between 50 and 90 mmHg
• Dieting or wishing to lose weight
• Pregnant woman or wishing to be pregnant or breastfeeding (interrogation data)
• Alcoholism or abuse or dependence on another proven drug. Consumption of more than 3 alcoholic beverages per day is considered abusive. An alcoholic beverage is 30 mL of spirits, 120 mL of wine or 330 mL of beer
• Donation of blood in the 2 months preceding the selection visit
• Subjects consuming dietary supplements
• Subjects refusing to follow the dietary instructions on the 3 days preceding the test day