Protein Digestibility of Whey and Zein.

Objective: This study aims to determine the digestibility of amino acids in two protein sources in men and women with normally functioning ileostomies.

Study design: Intervention study with 6 test days, testing 3 meals each twice. Study population: Eight men and women with normally functioning ileostomies will be recruited for the study.

Intervention: On six separate test days, subjects will receive a meal, consisting of a drink and biscuit. With this, two different protein containing meals, i.e. zein and whey, and a protein-free meal is tested; these three treatments are given at two occasions, thus in total 6 meals are tested. After consumption of the meal, subjects collect their digesta for nine hours.

Main study parameters/endpoints: Ileal amino acid digestibility of zein and whey protein isolate.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The subject will not benefit from the study except for the contribution to scientific research. The risk of participating to this study is low, some gastrointestinal discomfort could occur. Subjects have to come to the research facility seven times, a screening visit of 1 hour, and 6 experimental days of 10 hours. Subjects will be financially compensated for participation.

Inclusion criteria

• Male or female
• Age between 18 and 60
• Willing to eat animal protein
• Have a well-established and normally functioning terminal ileostomy, with stomal faeces of normal physiological consistency
• Good general health, meaning subjects should be well-recovered from the ileostomy operation, their underlying disease should be cured or in remission and they should not have any other major health problems

Exclusion criteria

• Taken antibiotics or medication that majorly impair small intestinal digestion and absorption within eight weeks of participating in the study.
• Have been pregnant or breastfeeding in the last 12 months, or plan to become pregnant during the study
• Having renal impairment, coeliac disease or diabetes
• Drug abuse
• Alcohol consumption of >14 units per week.
• Having an allergy or intolerance to dairy, corn products or fructose
• Currently taking protein supplements and would not be willing to stop using these during the study
• Being on a controlled diet or dietary weight loss regimen during the two weeks prior to the start of this study and/or during the study
• Personnel of division of Human Nutrition, Wageningen University..
• Current participation in other research from the Division of Human Nutrition
• Not having a general practitioner