In the current study the investigators aim to assess the nutritional quality and bio-functional activity of two alternative protein sources bovine plasma and corn and from the benchmark protein whey. The study is a double blind, randomised, cross-over, short-term trial in which 36 healthy study subjects will receive three protein interventions of 1 week with a washout period of 1 week between interventions. Study subjects will visit the research facility before and after the intervention period on two separate occasions to measure gut permeability via a multi-sugar test and to collect fasting blood samples and blood pressure outcomes. Faecal and saliva samples before and after each intervention will be collected. A subgroup of 12 study participants will also be subjected to a postprandial digestibility test on the first day of the interventions. The main study parameter is to assess the protein digestion kinetics and protection of the epithelial barrier. Secondary study parameters include other markers of gastrointestinal health, metabolic health, vascular health and satiating properties.

In the current study the investigators aim to assess the nutritional quality and bio-functional activity of two alternative protein sources bovine plasma and corn and from the benchmark protein whey. The objective is to assess the degree of digestibility and protection of the epithelial barrier of two alternative protein concentrates from corn and bovine plasma and of the commonly consumed benchmark protein whey. These outcomes will also be used to evaluate how predictive the in vitro-measurements have been for the obtained in vivo-effects. Secondary objectives are to assess the impact on other markers of gastrointestinal health, metabolic health, vascular health and satiating properties. Study design: The study is a double blind, randomised, cross-over, short-term trial in which 36 study subject will participate. Study subjects will receive three protein interventions of 1 week with a washout period of 1 week between interventions. Study subjects will visit the research facility before and after the intervention period on two separate occasions to measure gut permeability via a multi-sugar/acetylsalicylic acid test and to collect fasting blood samples and blood pressure outcomes. Faecal and saliva samples before and after each intervention will be collected. All measurements will be conducted after an overnight fast and a standardised evening meal prior to the study days. A subgroup of 12 study participants will also be subjected to a postprandial digestibility test on the first day of the interventions.

Study population: healthy study subjects, between 35-70y, BMI 18 - 30kg/m2, both males and females.

Intervention (if applicable): Three intervention arms of one week; a bovine plasma protein intervention, a corn protein intervention and a whey protein comparator intervention. Study subjects will receive 40 grams of protein per day during the intervention in two 20 g doses.

Main study parameters/endpoints: The main study parameter is to assess the protein digestion kinetics and protection of the epithelial barrier. Secondary study parameters include other markers of gastrointestinal health, metabolic health, vascular health and satiating properties.

Inclusion Criteria:

• Healthy subjects
• Age between 35-70 y
• BMI between 18 - 30 kg/m2

Exclusion Criteria:

• Intake of medications known to change the inflammatory status (including proton pump inhibitors, anti-inflammatory medication (including NSAIDs)
• Having a history of medical or surgical events that may significantly affect the study outcome
• Kidney dysfunction (self-reported)
• Gastrointestinal disorders, constipation (defecation <3 times a week) or history of gastrointestinal surgery
• Allergies for our intervention products
• Recent use of antibiotics (<1 month prior to day 01 of the study)
• Not having a general practitioner
• Mental status that is incompatible with the proper conduct of the study
• Pregnancy or lactating
• Reported weight loss or weight gain of > 5 kg in the month prior to pre-study screening
• Reported slimming, medically prescribed, other (extreme) diet, or use of protein concentrates
• Not willing to give up blood donation during the study
• Current smokers
• Alcohol intake > 3 glasses per day
• Hard-drug abuse
• Participation in other clinical trials in the past month
• Being an employee or student of the department Consumer Science & Health group of Wageningen Food & Biobased Research

will not be shared

Proteins will be packed in non-transparent sealed sachets/jars and labeled with 'protein A/B/C'. Proteins will be flavored to mask taste