Food-dependent set-up of the DiDGI® dynamic in vitro system: Correlation with the porcine model for protein digestion of soya-based food

Abstract

The present study compared in vivo protein digestion in a miniature pig model with the dynamic in vitro system DiDGI®, using three digestive compartments (stomach, duodenum, and jejunum + ileum). Two soya-based meals-commercial soya milk and tofu-were studied, each with the same macronutrient content but different macrostructures. Our aim was to first deduce from the in vivo experiments in pigs key digestive parameters such as gastric pH, stomach emptying kinetics, and intestinal transit time, in order to design a relevant set-up for the dynamic in vitro system. Then, we compared digestive samples collected at fixed sampling times from both in vivo and in vitro models regarding different values related to proteolysis. We observed similar evolutions of gastric peptide distribution and duodenal proteolysis between models. Overall, apparent ileal digestibility of nitrogen was similar in vitro and in vivo and the differences between the two meals were conserved between models.

Keywords: Gastric emptying; Intestinal transit; Mini-pig; Soya milk; Tofu.