The formidable guardian: Type 3 immunity in the intestine of pigs

Well-intestinal health is crucial for better growth performance in pigs. Type 3 immunity, which is one of the three types of immune responses in mammals, plays a vital role in maintaining intestinal homoeostasis. Therefore, we initially introduce the type 3 immune cells in the intestine of pigs, including their distribution, development, and function. We then discuss the type 3 immune response under infection, encompassing bacterial, fungal, and viral infections. It also covers two major stresses in pigs: heat stress and weaning stress. Lastly, we discuss the effects of various nutrients and feed additives on the regulation of the type 3 immune response in pigs under infection. This review aims to contribute to the understanding of the interaction between infection and type 3 immunity in pigs and to illustrate how various nutrients modulate the type 3 immune response in pigs under diverse infections.