The role of gut microbiota in the health and disease of pigs

• The gut microbial ecosystem is fundamental in proper nutritional, physiological, and immunological functions of the pig. However, composition and function of a healthy microbial ecosystem have yet to be qualitatively and quantitatively defined to be used as a tool to maximize animal health and performance. • As efforts are made to reduce antibiotic use in swine production, the gut microbiota needs to be recognized for its capacity to enhance disease resistance. • Increasing diet complexity, by including cereal grains high in fermentable carbohydrates, is a sustainable option to increase microbial diversity and beneficial microbes, help prevent incidence of post-weaning diarrhea, and decrease sub-therapeutic antibiotic use. • Although currently limited by regulatory issues, the introduction of microbial communities that have evolved to protect the pig may increase diversity of the gut microbial ecosystem and provide further protection. © Fouhse, Zijlstra, and Willing.