Bacillus spp. as probiotics have been widely used in the aquaculture industry. This study was designed to investigate the dietary supplementation of Bacillus cereus QSI-1 with quorum quenching activity, on intestinal barrier and expression levels of innate immune genes. After 14 d of feeding, fish fed with Bacillus cereus QSI-1 exhibited a significant down-regulated gene expression of TNF, IL-8, and IL-10 in the intestinal mucosa, but up-regulated tight junction (TJ) proteins zonula occludens-1 (ZO-1) and occludin and adaptor protein myeloid differentiation factor 88 (MyD88) transcription. This is an indication that Bacillus cereus QSI-1 could enhance intestinal barrier function and activate the non-specific immune system of Crucian carp. At the end of the feeding trial, the Crucian carps in each group were anally infected with A. hydrophila YJ-1. The results showed that Bacillus cereus QSI-1 could prevent the inflammatory response caused by A. hydrophila infection. Histological (integrity of intestinal villi) and qPCR analyses suggested that Bacillus cereus QSI-1 could improve the intestinal barrier function. Taken together, these findings indicate that Bacillus cereus QSI-1 could increase the intestinal epithelial barrier function and innate immune function, and also has the potential to be an alternative agent instead of antibiotics in feed supplements in aquaculture.

芽孢杆菌属。因为益生菌已广泛用于水产养殖业。这项研究旨在调查日粮芽孢杆菌QSI-1的定额猝灭活性，肠道屏障和先天免疫基因表达水平的补充。饲喂14天后，蜡状芽孢杆菌QSI-1饲喂的鱼肠粘膜中TNF，IL-8和IL-10的基因表达显着下调，而紧密连接（TJ）蛋白的小带闭合-1（ZO-1）以及occludin和衔接蛋白髓样分化因子88（MyD88）的转录。这表明蜡状芽孢杆菌QSI-1可以增强肠屏障功能并激活Cru鱼的非特异性免疫系统。在饲养试验结束时，各组中的鲫鱼进行肛门感染嗜水YJ-1。结果表明，蜡状芽孢杆菌QSI-1可以防止由炎症反应嗜水感染。组织学（肠绒毛的完整性）和qPCR分析表明蜡状芽孢杆菌QSI-1可以改善肠屏障功能。综上所述，这些发现表明蜡状芽孢杆菌 QSI-1可以增强肠道上皮屏障功能和先天免疫功能，而且在水产养殖饲料补充剂中也有可能替代抗生素。