Blood glucose prediction is very important for diabetic control and dietary management. To predict the influences of food properties on the postprandial blood glucose level, modeling the details of digestion process in the intestinal tract is the top priority. However, current models cannot deal with intrinsic granular properties, e.g., initial particle size, and intestinal physiological features, e.g., wall motility. This project addressed this problem from granular scale and intestinal scale, repectively. To account for the effects of intrinsic granular properties, we firstly developed a starch particle hydrolysis model that characterizes hindered enzyme diffusion and substrate hydrolysis on the surface and in the interior of porous starch particles. After validated by in-vitro digestion experimental data, this model is also able to identify the digestion pattern of different starch particles. Next, the particle-scale hydrolysis model was seamlessly coupled with an 1D intestine-scale parameter distributed model to predict the starch digestion in the intestinal tract. The multiscale model is capable of identifying temporal and spatial evolutions of particles in the intestine. By incorporating additional glycemic-related processes, e.g., intestinal absorption, a dietary property-based glycemic prediction system has been developed. Recently, with various intestinal physiological features, e.g., curved geometry, wall motility and electrolyte secretion, a 3D multi-physics duodenal model was constructed to simulate the digestion of starch particles in a near-real duodenum. Based on in-silico experiments, effects of these features on the in-vivo digestion behavior could be quantified. In conclusion, this project is expected to develop an intestinal digestion model taking both intrinsic granular properties and intestinal physiological features into account. More importantly, the modeling strategy we proposed is generic and can be applied to predict in-vivo bioavailability of other foods or drugs.

multiscale model, intestinal digestion, mass transfer, starch particles