Comparison of the Microbiome-Metabolome Response to Copper Sulfate and Copper Glycinate in Growing Pigs

This study aims to compare the fecal microbiome-metabolome response to copper sulfate (CuSO₄) and copper glycinate (Cu-Gly) in pigs. Twelve Meishan gilts were allocated into the CuSO₄ group and the Cu-Gly group (fed on a basal diet supplemented with 60 mg/kg copper from CuSO₄ or Cu-Gly) paired in litter and body weight. After a two-week feeding trial, the Cu-Gly group had a higher copper digestibility, blood hemoglobin, and platelet volume and higher levels of plasma iron and insulin-like growth factor-1 than the CuSO₄ group. The Cu-Gly treatment increased the abundance of the <i>Lachnospiraceae</i> family and the genera <i>Lachnospiraceae XPB1014</i>, <i>Corprococcus_3</i>, <i>Anaerorhabdus_furcosa_group</i>, <i>Lachnospiraceae_FCS020_group</i>, and <i>Lachnospiraceae_NK4B4_group</i> and decreased the abundance of the <i>Synergistetes</i> phylum and <i>Peptostreptococcaceae</i> family compared to the CuSO₄ treatment. Moreover, the Cu-Gly group had a lower concentration of 20-Oxo-leukotriene E4 and higher concentrations of butyric acid, pentanoic acid, isopentanoic acid, coumarin, and Nb-p-Coumaroyl-tryptamine than the CuSO₄ group. The abundance of <i>Synergistetes</i> was positively correlated with the fecal copper content and negatively correlated with the fecal butyric acid content. The abundance of the <i>Lachnospiraceae_XPB1014_group</i> genus was positively correlated with the plasma iron level and fecal contents of coumarin and butyric acid. In conclusion, Cu-Gly and CuSO₄ could differentially affect fecal microbiota and metabolites, which partially contributes to the intestinal health of pigs in different manners.