Digestive System Simulation And Blood Glucose Prediction:the Influence Of Dietary Management

As the diabetes problem becomes increasingly serious,blood glucose prediction,the key of glycemic control,has been the research hotspot of related fields.All the physiology parts in previous researches applied compartmental modeling approach,assuming that substrates in a compartment are distributed instantly and uniformly,and the parameters are all empirical constants.Therefore,such models cannot be used to evaluate the influence of food properties on postprandial blood glucose.The purpose of this study is to take both the food properties and the physiological characteristics of the gastrointestinal tract into account,simulate the physicochemical changes and mass transfer phenomena in the various parts of digestive tract with chemical reactor models,build the mechanistic model of the whole digestive system,and apply the established glucose-insulin regulation model to predict the postprandial blood glucose under different dietary condition.Firstly,this paper focused on the simulation of the hypoglycemic effect of soluble dietary fibers(SDFs)in oral glucose tolerance experiments.Taking into account the fluid absorption and absorption area evolution,the intestinal model with temporal and spatial distribution characteristics has been proposed and verified by previous clinical experiments.By resorting to this model,key glycemic lowering mechanisms(e.g.,delayed gastric emptying,glucose binding and viscosity change)have been systematically explored to identify dominant ones for different SDFs.It is revealed that,taking guar gum as an example,intestinal viscosity increase due to SDFs ingestion is the dominant mechanism.In addition,the simulation results show that the intake of sodium chloride can inhibit the hypoglycemic effect of soluble dietary fibers in result of the slowdown of intestinal water absorptionIn order to predict the blood glucose response of starchy food,the diffusion-reaction model of starch granules was also constructed in this paper.The model was verified by previous static digestion experiments,and coupled into the digestive tract model to explore the influences of granule size and environmental viscosity on the hydrolysis rate and glycemic response.In addition,since gastric emptying is one of the main rate-controlling steps of glucose appearance without any theoretical model yet,a static emptying model was preliminarily developed based on an in vitro bionic experiment and successfully used to predict the emptying rate under different viscosity.The experimental results show that the wall radial contraction may have little effect on emptying rate.