The gut tissues are important for feed intake and at the same time provide a niche for the microbiota. As a consequence, the gut is exposed to a vast variety of foreign antigens and has evolved a cellular network to ensure gut homeostasis. Maintaining this balance is important for optimal growth of pigs, especially during the critical periods of life. This chapter explores the latest findings in gut function and immunity in pigs as well as provides insights into how the microbiota can impact on these functions and shape intestinal immune responses. Finally, it discusses recent advances in the development of novel tools to investigate the functions of the gut tissues and provides an outlook to the future of gut health research in swine.