Development of novel in vitro human digestion systems for screening the bioavailability and digestibility of foods

The in vitro models employed have included all steps involved in digestion upon passage through the mouth, stomach, small intestine, and the colon. Importantly, enterobacter bacteria (Escherichia coli and Lactobacillus casei) are included to simulate the colon step. After in vitro human digestion in the small and large intestines, the antioxidant activity of rutin increased dramatically, whereas the antioxidant activity was not influenced by digestion in the mouth or the stomach. Before in vitro human digestion, the antioxidant activity of quercetin and chlorogenic acid was increased, and after in vitro human digestion in the small intestine and large intestines (with enterobacteria), the antioxidant activity of quercetin increased although enterobacteria did not influence the antioxidant activity. However, the antioxidant activity of chlorogenic acid was not influenced by in vitro human digestion in the small intestine and large intestines (with enterobacteria). This study provides data supporting an alternative to the use of animals and humans for rapid screening of food digestibility and bioavailability.