Effect of Dairy Matrix on the Postprandial Blood Metabolome

This study investigated the postprandial plasma metabolome following consumption of four dairy matrices different in texture and structure: cheddar cheese (Cheese), homogenized cheddar cheese (Hom. Cheese), and micellar casein isolate (MCI) with cream (MCI Drink) or a MCI Gel. An acute, randomized, crossover trial in male participants (n = 25) with four test days was con-ducted. Blood samples were collected during an 8-h postprandial period after consumption of a meal similar in micro-and macronutrients containing one of the four dairy matrices, and the metab-olome was analyzed using nuclear magnetic resonance (NMR) spectroscopy. A liquid dairy matrix (MCI Drink) resulted in a faster absorption of amino acids compared to products, representing either a semi-solid (MCI Gel and Hom. Cheese) or solid (Cheese) dairy matrix. For the MCI Gel, plasma concentration of acetic acid and formic acid increased approximately 2 h following con-sumption, while 3-hydroxybyturate and acetoacetic acid increased approximately 6 h after con-sumption. The structure and texture of the dairy matrix affected the postprandial absorption of amino acids, as revealed by the plasma metabolome. Our study furthermore pointed at endogenous effects associated with consumption of dairy products containing glucono-δ-lactone.