Influence of Factors on the gastrointestinal microbiota of Pigs

Abstract

A complete understanding of the dynamic distribution of the intestinal microbiota in pigs is essential because microorganisms play a fundamental role in physiological processes, immunity, and nutrient metabolism by the macroorganism. Disruption of the gut microbiome can cause inflammation, oxidative stress, and a cytokine storm. Gut microbiome dysfunction can be caused by short-term or long-term (environmental, nutritional, and stress) factors. The microbial ecosystem of the intestine is fundamental for the pig's proper nutrition, and physiological and immunological functions. However, the composition and function of a healthy microbial ecosystem have yet to be qualitatively and quantitatively determined to be used as a tool to maximize animal health and performance. As efforts are made to reduce the use of antibiotics in pig farming, the ability of the gut microbiota to increase disease resistance must be recognized. Generally, the genera Bacteroides, Escherichia, Clostridium, Lactobacillus, Fusobacterium, and Prevotella dominate in pre-weaning piglets. Then Prevotella and Aneriacter become the dominant genera, with Fusobacterium, Lactobacillus and Miscellaneous as relative minors in post-weaning piglets. Specific genera of bacteria, including Bacteroides, Prevotella, and Lactobacillus, can be detected in more than 90 % of pigs and three enterotypes – identified in animals of the same species but of different ages. This suggests the presence of a “core” microbiota in the gut of healthy pigs that may be a potential target for nutritional or health regulation. The scientists' scientific data help to determine the “optimal” gut microbial profile for evaluating or improving the performance and health status of pigs at different stages of growth. Although external and stochastic factors contribute to the individuality of the microbiota, the fundamental principles governing how environmental factors and host genetic factors combine to shape this complex ecosystem are largely unknown and require systematic study.