Toxicological effects of dietary nickel chloride on intestinal microbiota

摘要

This study was designed to evaluate the toxicological effect of dietary nickel chloride (NiCl_2) on the counts of intestinal bacteria and diversity of microorganisms in broilers. Plate counting and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) assays were used. A total of 240 one-day-old avian broilers chicks were divided into four equal groups and kept on corn-soybean basal diet along with supplementation of 0, 300, 600 and 900 mg/kg NiCl_2 for 42 days. Samples were taken at 21 and 42 days of age during the experiment. The bacterial count results showed that dietary NiCl_2 in the range of 300 to 900 mg/kg decreased the counts of Bifidobacterium spp. and Lactobacillus, increased Escherichia coli (E. coli) and Enterococcus spp. in the ileum and cecum. PCR-DGGE analysis showed that bacterial band numbers, profile similarity, and the Shannon index of the ileum and cecum were all decreased in the 300, 600, and 900 mg/kg groups at 21 and 42 days of age. In conclusion, dietary NiCl_2 affected the amount and diversity of intestinal microbiota in the ileum and cecum of broilers. This finding implies that NiCl_2 has toxicological effect on the intestinal ecosystem and, possibly functions.