Evaluation of the effects of dietary mycotoxin-degrading adsorbent on juvenile turbot (Scophthalmus maximus L.) fed aflatoxin B1-contaminated diets

This eight-week feeding trial was conducted to investigate whether adding yeast cell wall extract mixed with bacteria producing mycotoxin-degrading enzymes (YEMDE) to an aflatoxin B1 (AFB1)-contaminated diet affects the growth performance, liver health, antioxidant status, and intestinal microbiota status of juvenile turbot. A total of 480 fish were divided into four groups (three replicate tanks each group): basal diet (Control); Control diet supplemented with 100 mu g/kg AFB1 (AFB1); and AFB1 supplemented with 500 mg/kg or 1000 mg/kg YEMDE (AFY500 and AFY1000, respectively). The results showed that a minor variation in growth performance was observed among all groups (P > 0.05). Compared to the Control diet, the AFB1 diet significantly deceased the activities of triglyceride and catalase in the serum (P < 0.05); Compared to the Control diet, the AFB1 diet significantly increased the gene expression of cyp3a and apoptosis-related genes (p53, Bax, caspase3, caspase7 and caspase9) (P < 0.05), reduced the expression of catalase in the liver (P < 0.05); In addition, the AFB1 diet negatively changed the communities of intestinal microbiota and down-regulated the abundance of some po-tential probiotics Bifidobacterium and Stenotrophomonas (P < 0.05). However, both the AFY500 and AFY1000 diets markedly recovered the antioxidant capacity, inhibited the apoptosis of hepatocytes, and improved the communities of intestinal microbiota (P < 0.05). More positive effects were observed in the AFY1000 group. Compared to the AFB1 diet, the AFY1000 diet markedly increased the abundance of some potential beneficial bacteria in the intestine, such as Faecalibacterium and Lachnoanaerobaculum (P < 0.05). In conclusion, dietary YEMDE can effectively reduce the harmful impacts caused by AFB1 on turbot, and in particular, it had beneficial effects on the communities of intestinal microbiota. It is promising to use YEMDE to control AFB1 contamination in fish feeds.

Automated summary

This eight-week feeding trial investigated the effects of adding yeast cell wall extract mixed with bacteria producing mycotoxin-degrading enzymes (YEMDE) to an aflatoxin B1 (AFB1)-contaminated diet on the growth performance, liver health, antioxidant status, and intestinal microbiota status of juvenile turbot. The results showed that the AFB1 diet negatively impacted the liver health, antioxidant status, and intestinal microbiota of the fish, while the AFY500 and AFY1000 diets effectively improved these parameters. The AFY1000 diet had the most positive effects on the communities of potential beneficial bacteria in the intestine.