ReviewUse of brush border membrane vesicles to simulate the human intestinal digestion

- Small intestinal brush border membrane (BBM) accomplishes key digestion functions.
- Only a few simulated digestion experiments included an intestinal (jejunal) step.
- Simulating intestinal digestion with BBM hydrolases can provide physiological consistent results.
- Consensus protocols are required to develop extended in vitro digestion models.
- Forthcoming “gut-on-chip” devices or organoids might be adequate models of the human intestine.

The intestine presides over a series of vital functions in the human body, among which the digestion/absorption of nutrients. Despite their major digestion role, the impact of the enzymes of the luminal intestinal surface on food components has been considered in relatively few experiments of simulated gastrointestinal digestion. In contrast, the identification of proteolitically stable peptides which survived digestion in multiphasal models that also included a step with small intestinal brush border membrane (BBM) peptidases has provided physiologically consistent results. Herein, we critically review the use of BBM enzymes to simulate the intestinal digestion of dietary polypeptides. Addressing the controversial issue of the in vitro-in vivo correspondence of the digestion models, the review emphasizes the need to establish consensus protocols to simulate the intestinal step, for instance using the BBM hydrolases at least in a selected number of cases. The factors that have limited the development of relevant models of intestinal degradation are discussed together with hints to possible alternatives, forthcoming approaches and future perspectives to reproduce the physiopathology of the human small intestine.