A gut-associated Prevotellaceae_NK3B31_group lineage modulates host metabolic pathways and enhances feed efficiency in ducks
Amidst the mismatch between domestic feed supply and demand in China, along with the competition for food between humans and animals, optimizing feed efficiency has become crucial for industry growth. Nevertheless, the biological processes driving variations in feed efficiency remain unexplored. This research integrated analyses of production performance, gut microbiota, and host gene expression in ducks with varying feed efficiencies to investigate the regulatory mechanisms focused on intestinal metabolism.In this study, compared to LFE ducks, HFE ducks showed improved growth performance, including higher ADG, FE, and muscle deposition, alongside a reduced F/G and lower AFP, with no difference in ADFI. Further investigation revealed that the jejunum of HFE ducks exhibits a higher VH/CD ratio, as well as a general enhancement of the activity of key digestive enzymes, such as trypsin and lipase. In the jejunal contents, although overall microbial diversity remained unchanged, HFE ducks exhibited a marked increase in jejunal Prevotellaceae_NK3B31_group. Their abundances strongly correlated with host metabolites involved in amino acid and energy metabolism, suggesting a pivotal role in mediating feed efficiency. In the jejunal mucosa, transcriptomic analysis combined with RT-qPCR verification revealed coordinated upregulation of genes (e.g., PHGDH, PSAT1, SHMT2, PKM) driving the serine synthesis pathway, one-carbon metabolism, and glycolysis, indicating metabolic reprogramming. This metabolic state was accompanied by an enrichment of metabolites supporting protein synthesis and lipid catabolism. These host changes were strongly correlated with the enriched Prevotellaceae_NK3B31_group.The enhanced feed efficiency in HFE ducks was linked to enrichment of the gut-associated Prevotellaceae_NK3B31_group lineage in the jejunum, co-occurring with host metabolic reprogramming toward serine synthesis, glycolysis, and anabolic metabolism. These coordinated microbial and host alterations collectively underpinned the growth phenotype, providing novel insights into feed efficiency mediated by host-microbial metabolic interactions