FAYETTEVILLE, Ark. – A team of researchers from the Department of Animal Science at University of Arkansas recently published an article on their findings from a longitudinal study of the swine gut microbiome. 

The article, "Longitudinal investigation of the swine gut microbiome from birth to market reveals stage and growth performance associated bacteria," was first published online in late July and features contributions from a number of researchers, including: Xiaofan Wang, Tsungcheng Tsai, Feilong Deng, Xiaoyuan Wei, Jianmin Chai, Joshua Knapp, Jason Apple, Charles V. Maxwell, Jung Ae Lee, Ying Li and Jiangchao Zhao. 

"We are excited to publish our research on the Microbiome journal," said Zhao, associate professor of animal science. "This is an excellent team effort."

The article details research that sought to fill in the existing knowledge gap which shows that, despite recent advances in the understanding of the swine gut microbiome at different growth stages, a comprehensive longitudinal study of the lifetime (birth to market) dynamics of the swine gut microbiome is still lacking. 

"Following the human microbiome research area, lots of progress has been made in the swine gut microbiome in recent years," said Zhao. "However, most of these studies are either cross-sectional or sporadic with few sampling points. Many important biological and ecological questions are still unknown in this field."

The study itself involved the repeated collection of a total of 273 rectal swabs from 18 pigs during the lactation, nursey, growing, and finishing stages. DNA was then extracted from these samples and subjected to sequencing, before being analyzed using a process called the Deblur algorithm. The final results produced observable, distinct shifts in microbiome structure along different growth stages. It was also discovered that diet, especially crude fiber from corn, was a major factor in shaping the swine gut microbiome.

"The longitudinal design with many sample collections from the same set of pigs across different growth stages allowed us to understand how the swine gut microbiome changes over time and to identify the passengers and residents of the swine gut," said Zhao.

Utilizing the results from this study, the group concluded that the distinct stage-associated swine gut microbiome may be determined by the differences in diet and/or gut physiology at different growth stages. The results also emphasize the importance of optimizing stage-specific probiotics aimed at improving animal health and productivity. 

This comprehensive longitudinal study remarkably expanded the understanding of the swine gut microbiome and addressed several key ecological questions, such as: How does the swine gut microbiome change from birth to market across all the different growth stages? And, what are the key drivers shaping the swine gut microbiome during these stages?

"A well designed and controlled longitudinal study with a parallel validation trial is critical to reveal the underlying mechanisms of the swine gut microbiome development," said Zhao. "This study not only filled our knowledge gaps but also allowed us to identify several growth performances associated bacterial strains. Dr. Xiaofan Wang, the lead author of this paper, has isolated these strains by a culturomics approach. When we fed pigs with these beneficial bacteria, they significantly increased the growth performance of pigs. This is a great example of how to translate basic research to animal production."