Interaction of protease‐resistant potato proteins to the membrane proteins on small intestine changes the activities of digestive enzymes and gut microbiome profile in rat

Potato has been known to improve indexes on metabolic syndromes, such as, increasing insulin sensitivity and lowering plasma triglyceride level. In our previous studies, we found that the major potato proteins are resistant to the digestive enzymes. We hypothesized that the protease resistance potato proteins might interact with the small intestinal mucosa layer, then, trigger certain functional changes in the intestine. To investigate the functionalities of potato proteins on the intestine, the interaction complex of potato proteins to the small intestine mucosa layer was isolated by affinity crosslinking and purification, and identified by mass spectrometry analysis. Cell signaling changes by potato protein were analyzed by phosphoproteomic analysis. The identified interacting potato proteins were identified mainly as protease inhibitors. While, the counterpart intestinal membrane proteins could be grouped into digestive enzymes and channel proteins. Potato proteins showed a significant decrease in lipase activity and to increase in α‐glucosidase activity. Gut microbiome profile change were analyzed for the high fat diet fed mice with and without supplementation of potato proteins. The ratio of Fermicutes over Bacteroidetes and the complexity of microbiota were significantly recovered to those of nomal diet fed mice when potato proteins were supplemented to high fat diet.