Effects of dietary zearalenone on the serum biochemistry,hepatic and intestinal histology,and intestinal microbiota of juvenile Dabry′s sturgeon (Acipenser dabryanus)

Zearalenone (ZEN) is a common contaminant in animal feed, but the adverse effects of ZEN on the intestinal microbiota of fish have not yet been investigated. To reveal the effects of ZEN on serum biochemistry, hepatic and intestinal histology, and intestinal microbiota of fish, Dabry′s sturgeon (Acipenser dabryanus) received feed containing 1030 μg kg⁻¹ ZEN (ZEN-treated group) for 7 weeks and were compared to a control feed that have not been fortified with ZEN (control group). The results showed that dietary supplementation with ZEN did not significantly affect the serum contents of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, high-density lipoprotein cholesterol (HDLC) and estradiol (E₂; p > .05). The serum contents of total protein, albumin, triglycerides, total cholesterol and low-density lipoprotein cholesterol in the ZEN-treated group were significant lower than the control group (p < .05). The serum contents of glucose in the ZEN-treated group was significant higher than the control group (p < .05). Intestinal histology was normal in the ZEN-treated group with comparsion to the control group. Compared to the control group, the appearance of nuclear pyknosis and vacuoles in the hepatic cell in the ZEN-treated group. The α-diversity index (Chao 1, Faith pd and Shannon diversity index) significant increased in the ZEN-treated group compared to the control group (p < .05). Simpson diversity index was not affected by the dietary ZEN-treated (p > .05). Principal coordinates analysis (PCA) showed different clustering of prokaryotic communities in the ZEN-treated group compared to the control group. Further Anosim (Analysis of similarities) found that significnat differences in species community structure composition (R > .44) between the control group and the ZEN-treated group (p < .05). The number of operational taxonomic units (OTUs) was decreased after Dabry's sturgeon were fed diets supplemented with ZEN. At the genus level, the differences in the relative abundances of the first 20 main microbiota genera were considerable. In summary, this study suggests that dietary containing 1030 μg kg⁻¹ ZEN may be interfere with physiological parameters, and also affect the intestinal microbiota α-diversity, the numbers of OTUs and the microbiota compostion at the genus level of the juvenile Dabry′s sturgeon.