Chronic dietary deoxynivalenol exposure interferes the intestinal microbial community structure and antibiotic resistome in laying hens

Antibiotic resistance genes (ARGs) are critical emerging pollutants that have attracted considerable attention. Deoxynivalenol (DON) is one of the most prevalent mycotoxins in cereal crops worldwide, arising severe health hazards to both humans and animals. Even if numerous researches argue in favor of a notorious influence of DON on the gut, the effects of dietary DON exposure on the ARG profile in poultry intestine remain obscure. In this study, two separate feeding experiments using Jing Tint 6 laying hens exposed to 4.5 or 9.0 mg/kg DON were performed to explore the impact of dietary DON exposure on the microbial community structure and the profiles of ARGs in the intestine via 16S rDNA sequencing and metagenomics sequencing, respectively. In addition, growth performance and intestinal barrier function were also determined to assess the feasibility of using DON-contaminated feedstuffs inappropriate for pigs' consumption in laying hens. Chronic ingestion of DON at 9.0 mg/kg did not alter zootechnical parameters. However, histomorphological impairments were observed in liver and jejunum. Additionally, metagenomic sequencing revealed that dietary DON exposure at 9.0 mg/kg level dramatically changed the gut microbial structure and shifted the ARG profile. The abundance of tetracycline ARG subtype in the layer cecum was decreased, whereas the abundance of vancomycin ARG subtype was increased upon DON exposure. Co-occurrence network analysis identified that Prevotella was the major ARG host in the intestine of laying hens. In summary, our findings demonstrated that DON-contaminated feedstuffs inappropriate for pigs' consumption should be prudently used in hen production, and shed new light on the interactions between mycotoxins and ARGs in the poultry intestine.