Mercury (Hg) poisoning in humans and fish represents a significant global problem. Hg is one of the most dangerous threats to the aquatic ecosystem due to its high toxicity. Mercury has a high oxidative stress-inducing potential, and can compounds exert toxic effects by interacting with many important enzymes involved in the regulation of antioxidants. Selenium (Se) supplementation can reactivate the mercury-inhibited enzymes viability. The probiotic Bacillus subtilis is widely used in aquaculture, and it has a certain adsorption effect on heavy metals. The interactions between Hg and Se have been rigorously investigated, particularly due to the observed protective effects of Se against Hg toxicity. The objective of this study was to evaluate whether Se-rich B. subtilis ameliorated Hg-induced toxicity in C. carpio var. specularis. Fish were exposed to waterborne Hg (0.03 mg/L) and fed a diet supplemented with 10⁵ cfu/g Se-rich B. subtilis for 30 days. Fish were sampled, antioxidant activity, and Intestinal damage repair were assessed. Our results indicated that Se-rich B. subtilis protected the Intestinal from Hg-induced morphological changes. Hg treatment significantly decreased the activity levels of SOD, CAT and GSH-PX while increasing the activity levels of MDA, GST, and GSH. Hg treatment also upregulated the mRNA expression of Nrf2, CAT, GSH-PX and HO-1, and reduced expression of keap1. Se-rich B. subtilis had a significant protective effect against Hg-induced oxidative stress.

人和鱼中的汞（Hg）中毒代表了一个重大的全球性问题。汞由于其高毒性，是对水生生态系统最危险的威胁之一。汞具有很高的氧化应激诱导潜力，并且可以通过与参与抗氧化剂调节的许多重要酶相互作用来使化合物发挥毒性作用。补充硒（Se）可以重新激活汞抑制酶的活力。益生枯草芽孢杆菌广泛用于水产养殖，对重金属有一定的吸附作用。严格研究了Hg与Se之间的相互作用，特别是由于观察到Se对Hg毒性的保护作用。这项研究的目的是评估是否富硒枯草芽孢杆菌改善了汞对C.carpio var的毒性。镜面镜 将鱼暴露于水银汞（0.03 mg / L）中，并饲喂补充有10 ⁵  cfu / g富硒枯草芽孢杆菌的日粮30天。对鱼取样，评估抗氧化活性，并评估肠道损伤修复。我们的结果表明，富含硒的枯草芽孢杆菌可保护肠道免受汞诱导的形态变化的影响。汞处理显着降低了SOD，CAT和GSH-PX的活性水平，同时增加了MDA，GST和GSH的活性水平。汞处理还上调了Nrf2，CAT，GSH-PX和HO-1的mRNA表达，降低了Nrf2，CAT，GSH-PX和HO-1的mRNA表达。keap1。富硒枯草芽孢杆菌对汞诱导的氧化应激具有明显的保护作用。