Changes in Microbial Ecosystems and Serum Metabolomics by Diet Supplementation With Enramycin in Weaning Piglets

Antibiotics are used in swine production for growth promotion and disease prevention, raising concerns about environmental contamination and antibiotic resistance. In this study, we investigated the effects of enramycin supplementation on piglet growth, gut microbiota and blood metabolites. Enramycin promotes piglet growth and temporarily reduces diarrhoea. Gut microbiota analysis revealed changes in microbial composition, including an increase in the abundance of Limosilactobacillus reuteri. Metabolomic analysis has identified elevated levels of dimethylglycine, a known growth-promoting factor, in the enramycin group. Liver gene expression analysis revealed increased mRNA levels of ALDH and dimethylglycine dehydrogenase, which are enzymes involved in dimethylglycine metabolism. The enramycin-treated group had a higher concentration of acetic acid in caecal contents, and their caecal acetic acid concentrations were positively correlated with the abundance of L. reuteri and the content of serum dimethylglycine, respectively. These findings suggest that the promotion effect of enramycin on piglet growth is related to the gut microbiota, blood metabolites and liver gene expression, which provide insights into antibiotic alternatives for swine production.