Nano-selenium supplementation promotes reduction of antibiotic resistance genes and microbes-host interactions in Hainan Black Goats

Livestock farming is a major source of antibiotic resistance in the environment. Although supplementing selenium improves the GI-tract microecosystem and host metabolomes, nano-selenium effects on rumen microbiome and resistome remain limited. Here, multi-omics were performed to classify nano-selenium effects on rumen antibiotic resistance genes (ARGs) reduction, microbiome, metabolites, and host phenotypes on Hainan Black Goats. Increased growth performance, serum growth hormone, and antioxidant parameters by nano-selenium were observed. Nano-selenium significantly decreased the total ARG reads, MLS, and Tetracycline in the rumen. A strong correlation between the rumen resistome and microbiome was found. Nano-selenium increased the abundances of species of Prevotella and Fibrobacter . Moreover, nano-selenium enhanced carbohydrate metabolism and vitamin biosynthesis. Rumen fermentation parameters and metabolites related to carbohydrate utilization and antioxidant capacity were influenced by nano-selenium. Actinobacteria decreased by nano-selenium was associated with major ARGs related to Multidrug and Tetracycline. Structural Equation Modeling revealed that nano-selenium regulated MLS and Tetracycline for ARG reduction, and modulated the microbiome to improve rumen microbiome function. Overall, feeding proper concentrations of nano-selenium effectively reduces ARG pollution in vivo, and improves rumen microecosystem, growth, and antioxidant capacity in goats via microbiome modulation. These findings evidence that nano-selenium could benefit the goat industry, green food, and One Health.