Some dietary fibres, including wheat fibres, have shown to increase fecal bulk and improve stool. In previous studies, this effect on fecal bulk was especially studied for intact wheat fibers. Moreover, in most studies, the wheat fiber was offered daily as a single dose in cereals. In this study, we investigate whether an increased intake of extracted wheat fiber, implemented at several time points in a normal daily dietary pattern, can also increase fecal bulk and improve stool frequency and consistency. Here we want to demonstrate that an increase in VITACEL Wheat Fiber intake will enhance fecal bulk, both wet and dry weight and that the enhanced wheat fiber intake will also increase stool frequency and consistency. The study is a double-blind crossover design in which the intervention is based on products enriched by VITACEL Wheat Fiber and control products. Both the control and fiber-enriched intervention will last for 10 days with a wash-out period of at least 4 days. The study will be conducted with 25 healthy male human volunteers in the age between 18-70 years old.Persons will be assigned to the intervention groups. In one of the intervention periods participants receive 'control boxes' with products low in wheat fiber and in the other period they will receive boxes with products enriched with VITACEL Wheat Fiber. During an intervention period of 10 days participants will receive 10 boxes, one for each day. In the last 5 days of the intervention + 1 additional day after the intervention (so in total 6 days), participants will collect their fecal samples to analyse fecal bulk. Daily also a diary has to be kept and questionnaires have to be completed to check compliance to the intervention and assess stool consistency, gut-related complaints.

Inclusion Criteria:

• Male
• Apparently healthy (no gastrointestinal complaints, no food allergies and no medication that can influence the outcome of this study
• Age range between 18-70 years old
• BMI between 20 and 30 kg/m2
• Average fiber intake of <23grams per day
• Living in the surrounding area of Wageningen (radius ~20 km)

Exclusion Criteria:

• Any digestive tract disorder that is expected to interfere with this study (e.g. (partial) gastric resection, (hemi)colectomy, Crohn's disease, ulcerative colitis, irritable bowel disease, Coeliac disease)
• Known food allergy (e.g. lactose, gluten, nuts, egg, etc)
• Vegetarians
• Use of pro- or prebiotics
• Use of medication that can interfere with study outcomes (including laxatives, diuretics, antidepressants, codeine or antibiotics)
• Alcohol intake ≥ 40g/day (≥ 3 glasses of beer/wine per day)
• Drug abuse
• Current smokers
• Participation in other clinical trials in the past month