Integrity of gut barrier is the foundation of the multiple function of intestinal tract to keep normal.Dietary conditionally essential amino acids are major fuels for the small intestinal mucosa as well as important substrates for syntheses of intestinal proteins,nitric oxide and metabolic products,and are required for maintaining intestinal integrity.The article reviewed recent advances in dietary uses of functional amino acids(including glutamine,glutamate,and arginine) to enhance the gut health and immune status of animals.