The chicken cecal microbiome alters bile acids and riboflavin metabolism that correlate with intramuscular fat content

Intramuscular fat (IMF) is a key indicator of chicken meat quality and emerging studies have indicated that the gut microbiome plays a key role in animal fat deposition. However, the potential metabolic mechanism of gut microbiota affecting chicken IMF is still unclear. Fifty-one broiler chickens were collected to identify key cecal bacteria and serum metabolites related to chicken IMF and to explore possible metabolic mechanisms. The results showed that the IMF range of breast muscle of Guizhou local chicken was 1.65 to 4.59%. The complexity and stability of ecological network of cecal microbiota in low-IMF chickens were higher than those in high-IMF chickens. Cecal bacteria positively related to IMF were <i>Alistipes</i>, <i>Synergistes</i> and <i>Subdoligranulum</i>, and negatively related to IMF were <i>Eubacterium_brachy_</i>group, <i>unclassified_f_Lachnospiraceae</i>, <i>unclassified_f_Coriobacteriaceae</i>, <i>GCA-900066575</i>, <i>Faecalicoccus</i>, and so on. Bile acids, phosphatidylethanolamine (Pe) 32:1 and other metabolites were enriched in sera of high-IMF chickens versus low-IMF chickens while riboflavin was enriched in sera of low-IMF chickens. Correlation analysis indicated that specific bacteria including <i>Alistipes</i> promote deposition of IMF in chickens via bile acids while the <i>Eubacterium_brachy</i> group, and <i>Coriobacteriaceae</i> promoted formation of riboflavin, glufosinate, C10-dats (tentative), and cilastatin and were not conducive to the IMF deposition.