On designing biomimic in vitro human and animal digestion track models: ideas, current and future devices

In recent years, there has been an increasing interest in the development of advanced in vitro digestion systems to study the fate of foods during digestion in the gastrointestinal (GI) tract. This is particularly important to understand the physiological effect of foods on human health and to develop healthy foods with desired functions. Here, the representative in vitro systems (testing devices) already reported in literature are summarized and critically reviewed. The gross GI morphology and anatomical structures in humans and rats those are likely to have considerable effect on food digestion are described. The motivations, ideas and mechanisms of the biomimic dynamic in vitro rat and human stomach-intestine devices are presented in particular to show where we are at in this field. Despite that the valuable scientific insights have been gained through the current in vitro GI models, none of them seen to have effectively mimicked the aspects of GI morphology and anatomy. These should be taken into account along with the related biochemical environments and peristaltic movements occurring in vivo, in order to show the way forward for the development of more realistic in vitro models.