Amino Acid Kinetics of GMP-AA in Healthy Human Volunteers

Children with phenylketonuria (PKU) are treated with a special diet supplemented with a synthetic protein based on amino acids. These have a poor taste and are inefficiently used by the body. A different type of synthetic protein, called glycomacropeptide is being tried in PKU. It tastes better than amino acids but it requires the addition of some extra amino acids which may worsen how well it is absorbed compared with traditional amino acid supplements. We will perform a 3-part trial in healthy adult volunteers to compare amino acids vs glycomacropeptide protein with a 'normal protein' (casein) to examine the absorption properties of these proteins. Volunteers will take one dose of each of the protein sources on 3 different days. Blood and urine samples will be collected examining the rate of absorption of amino acids over 5 hours on each study day.