Abstract
The gut microbiome is essential to animal health. Many factors, including both environmental (e.g. diet) and host-related (e.g. genetic background, sex, age), shape the intestinal microbiome. Pioneers in gut microbiology have stressed the critical importance of interactions among the diet, the gut microbiota, and the host on animal health and disease. Different protein types (e.g. plant-based vs. animal-based) have been shown to have differential effects on the gut microbiome. In addition, there is evidence of compartment-specific and amino acid-specific interactions that occur within the gastrointestinal tract. The result of these interactions must be considered to be essential as a variety of metabolites are produced and, for example, act as nutrients and modulators of physiologic processes. Our overarching goal is to discuss protein/amino acid effects on pig microbial ecology, health, and nutrition.