Intestinal bacteria and their influence on swine growth

The gastrointestinal (GI) tract of the pig harbors a numerically dense and metabolically active microbiota comprising mainly bacteria. Indeed, all animals have, and seemingly require, long-term cooperative associations with indigenous bacteria in the GI tract. Studies with gnotobiotic animal models demonstrate most conclusively that indigenous bacteria stimulate the normal maturation of host tissues and provide key defense and nutritional functions. This commensal relationship has been selected over evolutionary time resulting in a stable microbiota in mature animals that is generally similar in composition and function in a diverse range of animal species.