APOA4 and digestive system disorder: In the gastric tissues of T2DM gastroenteropathy, the current study showed downregulation of Apob gene expression, upregulation of Tcn2 protein expression, downregulation of Apoa4, Apoa1, and Rnlip protein expression, and upregulation of key metabolite expression of Pantothenic acid in the pathway of vitamin digestion and absorption.