REVIEW: The pig as a model for humans: Effects of nutritional factors on intestinal function and health

Abstract

The porcine model has been utilized by researchers to study human developmental aspects, surgical procedures, disease impacts, and nutritional interventions for over 60 yr. However, when it comes to investigating how nutrients regulate human gastrointestinal tract (GIT) function and health, and nutritional research evolves from dietary composition to potential nutraceutical applications, the question needs to be asked: is the pig an appropriate translational animal model? Morphologically and functionally, the porcine GIT has more similarity to the human GIT than commonly used models such as rats. Food intake related to BW is much lower in humans than in pigs, which explains the higher and faster growth and earlier maturation in the latter species. In addition, the digestion and metabolism of carbohydrates, prebiotics, lipids, and amino acids produce similar metabolites and subsequent effects on GIT development and health in pigs and humans, making the pig a more comparable model to study human GIT issues than other nonprimate species. However, there are key divergences. Pigs have a functional cecum, larger colon, and the endogenous microbiota of the GIT, while similar at the phylum level is vastly different at the genera level. One notable microbial species that is low to nonexistent in the porcine GIT are the Bifidobacterium, which is a major probiotic species in humans. Several porcine models have been developed to overcome these issues, but they are new and have yet to be fully tested. This paper will provide a comparative analysis between the human and porcine GIT in regards to structure, function, and health and how various nutritional factors influence these characteristics and future developments of the porcine model.

animal models, gastrointestinal tract, human, nutrition, pig, translational research

© American Society of Animal Science 2016