The School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK.
Food Funct. 2020 Nov 18;11(11):9397-9431. doi: 10.1039/d0fo01981j.
The gold standard for nutrition studies is clinical trials but they are expensive and variable, and do not always provide the mechanistic information required, hence the increased use of in vitro and increasingly in silico simulations of digestion. In this review, we give examples of the main simulations being used to model upper gastrointestinal tract digestion. This review ranges from the selection of enzymes to the interpretation of results from static models to fully dynamic models. We describe the modifications made to accommodate different demographic groups (infants, the elderly, etc.). We list examples of the application of the different models as well as giving the advantages and disadvantages. A model is only useful if it predicts or aids the understanding of physiological behaviour. Thus, the final section of the review makes a comparison of results obtained from experiments undertaken using in vitro simulations with those obtained in vivo. This comparison will help the reader understand the appropriateness of each model for the type of measurement to be undertaken. In particular, human studies tend to measure bioactive concentrations in blood and not in the gastrointestinal tract whereas in vitro studies often only produce data on release of nutrients into the gut lumen. This is the difficulty of comparing bioaccessibility as generated in vitro with bioavailability as generated in vivo. It is apparent that the models being used are increasingly being validated with in vivo data and this bodes well for the future.
营养研究的金标准是临床试验，但它们昂贵且多变，并不总是提供所需的机制信息，因此越来越多地使用体外和越来越多的计算机模拟消化。在这篇综述中，我们举例说明了主要用于模拟上消化道消化的模拟方法。这篇综述涵盖了从选择酶到解释静态模型到完全动态模型的结果。我们描述了为适应不同人群（婴儿、老年人等）而进行的修改。我们列出了不同模型的应用实例，并给出了它们的优缺点。如果模型能够预测或有助于理解生理行为，那么它才是有用的。因此，综述的最后一部分将比较使用体外模拟进行的实验和体内实验获得的结果。这种比较将帮助读者了解每种模型对于将要进行的测量类型的适用性。特别是，人体研究倾向于测量血液中的生物活性浓度，而不是胃肠道中的浓度，而体外研究通常仅能提供关于营养素释放到肠腔中的数据。这就是体外产生的生物可及性与体内产生的生物利用度难以比较的原因。显然，正在使用的模型越来越多地用体内数据进行验证，这对未来是一个好兆头。
