Prevotella Copri Increases fat Accumulation in Pigs fed by Formula Diets

Abstract Background: Excessive fat accumulation of pigs is undesirable. It severely affects economic return of modern pig industry. Studies in humans and mice have examined the role of the gut microbiome in host energy metabolism. Commercial Duroc pigs are often fed formula diets with high energy and protein. Whether and how the gut microbiome under this type of diets regulates swine fat accumulation is largely unknown. Results: In the present study, we systematically investigated the correlation of gut microbiome with pig lean meat percentage (LMP) in a total of 698 commercial Duroc pigs. We demonstrate that the gut microbiome of fat pigs was dominated by P. copri which occupied 23.53% and 5.76% of relative abundance in average in the discovery and validation cohort, respectively. High abundance of P. copri in the gut resulted in a higher abundance of serum metabolites associated with chronic inflammation, e.g., branched chain amino acids, aromatic amino acids, the metabolites of arachidonic acid metabolism and lipopolysaccharides. Host intestinal barrier permeability and chronic inflammation response were increased. A gavage experiment using germ-free mice confirmed that the P. copri isolated from experimental pigs was a causal species increasing host fat accumulation. Host colon, adipose tissue, and muscle transcriptomes indicated that P. copri colonization significantly upregulated the expression of the genes related to immune and inflammatory responses, lipogenesis, and fat accumulation, but attenuated the genes associated with lipolysis, lipid transport, and muscle growth. Conclusions: Taken together, we identified and confirmed that P. copri in the gut microbial communities of pigs fed by commercial formula diets results in the significantly increased fat deposition of pigs, and proposed a possible mechanism of P. copri affecting fat accumulation. The results provided fundamental knowledges for reducing pig fat accumulation through regulating the gut microbial composition in pig industry.