Mycotoxins Deoxynivalenol and Fumonisins Alter the Extrinsic Component of Intestinal Barrier in Broiler Chickens

Abstract

Deoxynivalenol (DON) and fumonisins (FBs) are secondary metabolites produced by Fusarium fungi that frequently contaminate broiler feed. The aim of this study was to investigate the impact of DON and/or FBs on the intestinal barrier in broiler chickens, more specifically on the mucus layer and antioxidative response to oxidative stress. One-day-old broiler chicks were divided into four groups, each consisting of eight pens of seven birds each, and were fed for 15 days either a control diet, a DON-contaminated diet (4.6 mg DON/kg feed), a FBs-contaminated diet (25.4 mg FB1 + FB2/kg feed), or a DON+FBs-contaminated diet (4.3 mg DON and 22.9 mg FB1 + FB2/kg feed). DON and FBs affected the duodenal mucus layer by suppressing intestinal mucin (MUC) 2 gene expression and altering the mucin monosaccharide composition. Both mycotoxins decreased gene expression of the intestinal zinc transporter (ZnT)-1 and regulated intracellular methionine homeostasis, which are both important for preserving the cell's critical antioxidant activity. Feeding a DON- and/or FBs-contaminated diet, at concentrations close to the European Union maximum guidance levels (5 mg DON and 20 mg FB1 + FB2/kg feed) changes the intestinal mucus layer and several intestinal epithelial antioxidative mechanisms.

Keywords: broiler; deoxynivalenol; fumonisins; intestinal barrier; methionine; mucus; oxidative stress; zinc.