Gut microbiota composition in swine: genetic parameters and links with immunity traits


The intestinal microbiome plays a major role in host's physiology and homeostasis. It participates in the immunological barrier against infections, helps to develop and mature the immune system, and contributes to extract nutrients and energy from food. Despite large scale studies in human, little is known on gut microbiota composition and potential associations with individual traits in livestock species. The objective of this study was to estimate the genetic parameters of the gut microbiota composition and analyze its links with immunity traits in French Large White pigs. A cohort of 60 days old piglets was assessed for fecal microbiota composition by pyrosequencing the 16S rRNA gene. First results on 299 piglets showed a predominance of Prevotella followed by Oscillibacter, Dialister, Roseburia and Treponema. Among a set of 63 genera, 7 had low (0.1<h2<0.2), 15 medium (0.2<h2<0.4) and 8 high (h2>0.4) heritabilities for abundance variations. At the genetic level, the relative abundance of Prevotella, Oribacterium, Selenomonas, Dialister and Megasphaera were found positively correlated with each other and tended to be negatively correlated to other genera. Finally, regularized canonical correlations (rCCA) and sparse Partial Least Squares (sPLS) analyzes highlighted both positive and negative correlations between various immunity traits (e.g. monocytes, eosinophils, platelets) and genera such as Prevotella, Roseburia and Dialister. In this report we demonstrate for the first time that the gut microbiota composition in swine is influenced by the genetics of the host. In addition, we have found covariations between microbiota composition and immunity traits. These results pave the way for studying the microbiota as a new component of phenotype construction in pigs. Microbiota parameters together with zootechnical and immunity traits will help to better decipher the driving forces that shape animal performances and robustness.