Characteristics of gut microbiota and metabolomic of Hainan Tunchang pigs at various growth stages

Numerous gut microorganisms residing in the gut tract and their metabolites play an important role in animal growth. Diet, as the main factor, affects the changes of gut microbiota, and host genetics also have a significant impact on gut microbiota, including growth stages. However, the differences of gut microbiota and its metabolites at various growth stages in local pig breed remains unclear. We used 16S rRNA gene sequencing and untargeted metabolomics to investigate the fecal microbiota and metabolites in different developmental stages of Hainan Tunchang pigs. The relative proportions of dominant bacteria Firmicutes and Spirochaetes increased, Bacteroidetes and Proteobacteria decreased with the development. As age increased, different physiological states led to structural and functional changes in animal nutrition metabolism and immune needs, as well as changes in gut microbiota and its metabolites. We have detected several statistically different microbial and metabolic biomarkers at different growth stages. Meanwhile, through correlation analysis between differential bacteria and metabolites, it was found that the bacteria forming networks with their significant related metabolites were different at various growth stages, Holdemanella, Sharpea, Subdoligranulum, and uncultured_bacterium_o_Bacteroidales were enriched between preweaning piglets and weaning piglets, and they all positive correlated with related metabolites. We also found that the differential bacteria were significantly related to short-chain fatty acid. These findings might provide new insights into the developmental changes of gut microbiota in local pig breeds and the interaction mechanism between the body, and improve pig growth performance and efficiency by regulating the composition of gut microbiota and metabolites.