Genetic determination of phenotypes depends not only on the host genome but also on its microbiome, particularly that of the intestinal tract. Host and microbiome form a complex co-metabolism that ultimately affects relevant phenotypes, like the intramuscular fat content. The metabolomic analysis of the gut content can provide a functional characterization, giving a better insight into the microbiome activity implicated. The objective of this study was to unveil the genetically determined microbial metabolic pathways related to intramuscular fat deposition, a key meat quality trait in all species. To do so, the cecal metabolomic analysis of 2 rabbit lines divergently selected for intramuscular fat content was performed. Important differences between the divergent lines were found in their cecum metabolome, which pointed to the metabolism of secondary bile acids, purines, and several amino acids as the most relevant microbial pathways differentiating the intramuscular fat deposition of the lines. Additional analyses also suggested that there were different microbial pathways associated with the intramuscular fat deposition within each line. Finally, a biomarker composed of 4 microbial metabolites and with 88% classification accuracy was proposed, which pointed to lipid absorption and protein metabolism as relevant drivers of the microbiome activity influencing intramuscular fat deposition.

Read the full article in the Journal of Animal Science.