Gut metagenomes and 16S rRNA amplicons of piglets consuming low, medium or high concentrations of zinc oxide
Antimicrobial resistance is a major health concern globally where the livestock sector is standing out for its substantial use of antimicrobials to sustain productivity, but is also taking action to reduce the use of antimicrobials and invest in the development of mitigation strategies. In the swine industry, trace minerals are added to the feed to meet the animals nutritional requirements, or as alternatives to antibiotics. Supranutritional concentrations of zinc (Zn) are served to piglets to prevent post-weaning diarrhea. A practice not without concern as piglets do not fully assimilate high concentrations of Zn, which disturbs their oxidative status and uptake of other essential minerals. A large fraction is excreted and leads to accumulation of heavy metals in the environment through manure spreading, and contributes to the persistence of antibiotic resistance by co-selection. In this study, the gut microbiome and resistome were investigated using metagenomics and16S rRNA amplicon sequencing on samples of ileum and colon digesta of piglets fed either low (175 ppm), medium (953 ppm) or high (2291 ppm) concentrations of zinc oxide for 21 days after weaning. The evidence in this study supports the limitation of Zn to nutritional requirements, to avoid microbiome disruption and selection for antimicrobial resistance.