During this project the amount of SCFA produced in the colon after consumption of 2 different 13C-labelled wheat fiber fractions will be quantified.

Inclusion Criteria:

• Regular diet with 3 meals a day (minimal 5 times a week)
• BMI between 18.5 and 27 kg/m2

Exclusion Criteria:

• Calorie restricted diet or other special diet during the study or during the last month prior to the study
• Antibiotics in the month prior to the study
• Former surgeries on the gastrointestinal tract, with the exception of an appendectomy
• use of the following types of medications with effects on the gastrointestinal tract during the last 2 weeks prior to the study (spasmolytica, anti-diarrhea, anti-constipation, probiotics)
• Chronic disease of the gastrointestinal tract such as Crohn's disease, ulcerative colitis, irritable bowel syndrome, chronic constipation, chronic frequent diarrhea, clinically relevant lactose intolerance
• Pregnancy, pregnancy desire or breastfeeding
• Diabetes (type 1 and 2)
• Blood donation in the past 3 months prior to the study
• Abnormal hemoglobin (Hb) levels in blood, men must have a Hb level between 14.0 and 18.0 g / dL and women between 12.0 and 16.0 g / dL
• Participation in studies in the past year in which radiation was used.