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.

Susceptibility of Broiler Chickens to Coccidiosis When Fed Subclinical Doses of Deoxynivalenol and Fumonisins—Special Emphasis on the Immunological Response and the Mycotoxin Interaction

“…This effect on nutrient transporters has already been described during infection with E. maxima [34]. In unchallenged birds, our results are in agreement with Antonissen et al [10] that also showed that the Sa/So ratios in plasma of birds fed FB alone or in combination with DON were the same. Indeed, it was hypothesized that the known increase of paracellular permeability by DON (through its effects on tight junctions) could at the same time increase the passage of other toxics, such as FB.…”

“…Poultry have long-been considered relatively resistant to mycotoxins, especially to toxins from Fusarium . However, very recent investigations have shown that concentrations of mycotoxins below the EU and US limits or at concentrations lower than those that would cause overt clinical mycotoxicosis, may significantly affect the performance and health of birds [5,6,7,8,9,10]. Many reasons may account for these new findings.…”

Possible Role of Phosphatidylcholine and Sphingomyelin on Fumonisin B1-mediated Toxicity

“…Methionine deficiency in the pancreas may promote dysfunctions of pancreas in similar to those in rodents treated with CDE diet. Consistent with this idea, FB1 treatment resulted in the up-regulation of the intestinal brush border transporter B0AT and the basolateral transporter y+LAT1 in newborn chickens, suggesting the demand of an increased intracellular uptake of neutral amino acids such as methionine 148) .…”

“…Feeding FB-containing diet (FB1 + FB2 25.4 mg/kg feed) for 15 days to chickens resulted in altered glycosylation of mucin and in a decreased level of mucin 2 mRNA in the duodenum 148) . In addition, specific mRNA level of basolateral zinc transporter (ZnT1) was reduced in jejunum of FB-treated chickens 148) , which may contribute to maintain the zinc ion in brush border.…”

“…In addition, specific mRNA level of basolateral zinc transporter (ZnT1) was reduced in jejunum of FB-treated chickens 148) , which may contribute to maintain the zinc ion in brush border.…”