We investigated the effects of different levels of dietary Bacillus subtilis (BS) on innate immunity, growth performance, feed utilization, and disease resistance of juvenile olive flounder. A control diet was formulated without probiotic, and three other diets were prepared adding different doses (1 × 10⁷, 3 × 10⁷, and 5 × 10⁷ CFU/g feed) of BS (designated as Control, BS1, BS3, and BS5, respectively). Triplicate groups of fish (initial body weight, 25 g) were fed for 12 weeks. Fish fed BS‐containing diets showed significantly higher nonspecific immune responses than fish fed the control diet. Fish fed the BS5 diet showed significantly higher growth performance and feed utilization efficiency than fish fed the control diet. Fish fed the BS diets showed remarkably higher resistance against Streptococcus iniae than fish fed the control diet. These results indicate that BS supplementation at a dose of 5 × 10⁷ CFU/g diet can improve innate immunity, growth performance, feed utilization, and disease resistance against S. iniae in olive flounder.

中文翻译：

---

饮食中枯草芽孢杆菌对幼鱼比目鱼对免疫反应，血液学参数，生长性能和抵抗力的影响

我们调查了饮食中不同水平的枯草芽孢杆菌（BS）对幼年比目鱼天然免疫力，生长性能，饲料利用率和抗病性的影响。配制不含益生菌的对照饮食，并准备其他三种饮食，分别添加不同剂量（1×10 ^7，3 ×10 ⁷和5×10 ⁷  CFU / g饲料）的BS（指定为对照，BS 1，BS 3） ，和BS 5）。一式三份的鱼（初始体重25克）喂食12周。鱼饲料BS‐含饮食的鱼类比接受对照饮食的鱼类显示出更高的非特异性免疫反应。饲喂BS 5日粮的鱼比饲喂对照日粮的鱼表现出显着更高的生长性能和饲料利用率。饲喂BS日粮的鱼比饲喂对照日粮的鱼对猪链球菌的抵抗力明显更高。这些结果表明，以5×10 ⁷  CFU / g饮食的剂量添加BS可以提高先天免疫力，生长性能，饲料利用率以及对比目鱼的海豚链球菌的抗病性。