This collection features four peer-reviewed reviews on alternatives to antibiotics in pig production.The first chapter provides a brief overview of antibiotic use in pig production and addresses the consequent development of antibiotic resistance. The chapter reviews recent advances in developing non-antibiotic means of controlling bacterial infections in swine, such as the use of phage therapy. The second chapter considers the use of prebiotics to optimise gut function in pigs. The chapter summarises current knowledge on the effects of prebiotic oligosaccharides on porcine gut function and health, as well as the modes of action of the commonly used prebiotics in pig production. The third chapter reviews advances in nutritional strategies to boost immune function in pigs, including the use of lipopolysaccharide to stimulate the immune system. The chapter considers the need to reduce the use of antimicrobials in swine diets and reviews the effect of dietary supplementation during key stages of a pig’s life to enhance immunity. The final chapter reviews the microbiota of the gastrointestinal tract of the young pig and the important role it plays in the early stages of life. The chapter considers the use of probiotics and prebiotics in the post-weaning period of piglets to optimise gut function, animal health and performance.