Validation of an in vitro digestive system for studying macronutrient decomposition in humans

Abstract

In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. In this study, human digestion was simulated with a three‐step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS‐PAGE, reversed phase HPLC, size exclusion HPLC, and LC‐MS. The mean peptide size after in vitro digestion of pasteurized milk was 5–6 amino acids. Interestingly, mostly essential amino acids (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential amino acid concentration of bovine milk (44.5%). All triglycerides were degraded to free fatty acids and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges.This project is financially supported by the Swiss federal program NanoTera.Grant Funding Source: Swiss Ferderal Research Program NanoTera