Probiotics as dietary additives can improve weight gain, feed efficiency, and disease resistance in cultured fish. In this research, we evaluated and compared the effects of on immunity, mucosal tissue morphology, immune-related gene transcriptions, and intestinal microbiota in flounder () by a 30-day feeding experiment based on a continuous feeding schedule (E1) and a discontinuous feeding schedule (E2). As a result, the use of exerted the best positive effects on survival rate, enzyme activity, mucosal tissue morphology, immune-related gene transcriptions, and intestinal microbiota in flounders. Alkaline phosphatase (AKP), lysozyme (LZM), and superoxide dismutase (SOD) activities in the liver of E2 were higher than those of E1 ( < 0.05). Furthermore, the villi length in the intestinal tract and the fold length in the stomach of E2 were also higher than in E1 ( < 0.05). The expression levels in the spleen were significantly increased in E2 ( < 0.05) compared to E1. We performed 16 S rRNA sequencing analysis to find that in E1 (1.06%) and E2 (1.01%) had higher relative abundances than in E0 (0.053%) at the end of the experiments, indicating that short-term application of with the continuous or discontinuous feeding method can allow both the adaptation of the ecosystem to the presence of probiotics by the establishment of new species in the gut microbiota and the ability these new probiotic species to perform corresponding functions. No significant differences in the ability of probiotic establishment were observed between E1 and E2. Our findings provided a unique perspective to explore the mechanism of immune enhancement with probiotics and to screen the optimal administration strategy in aquaculture application for probiotic use. Together, these results point to some level of enhancement in immune status by continuous and discontinuous feeding after a short-term feeding period, which could be used as a prophylactic strategy for flounder health management.

中文翻译：

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枯草芽孢杆菌对牙鲆（Paralichthys olivaceus）两种喂养方式（连续与间断喂养）免疫、粘膜组织形态、免疫相关基因转录和肠道微生物群的影响

益生菌作为膳食添加剂可以提高养殖鱼类的增重、饲料效率和抗病能力。在本研究中，我们通过基于连续喂养计划（E1）和间断喂养计划的 30 天喂养实验，评估并比较了比目鱼（）对免疫、粘膜组织形态、免疫相关基因转录和肠道微生物群的影响。喂养时间表（E2）。结果，使用对比目鱼的存活率、酶活性、粘膜组织形态、免疫相关基因转录和肠道微生物群产生了最佳的积极影响。 E2 肝脏中碱性磷酸酶（AKP）、溶菌酶（LZM）和超氧化物歧化酶（SOD）活性均高于 E1（ < 0.05）。此外，E2的肠道绒毛长度和胃褶皱长度也高于E1（<0.05）。与E1相比，E2中脾脏中的表达水平显着增加（<0.05）。我们进行了 16 S rRNA 测序分析，发现在实验结束时，E1 (1.06%) 和 E2 (1.01%) 的相对丰度高于 E0 (0.053%)，这表明短期应用连续或不连续喂养方法可以通过在肠道微生物群中建立新物种来使生态系统适应益生菌的存在，并使这些新益生菌物种具有执行相应功能的能力。 E1 和 E2 之间没有观察到益生菌建立能力的显着差异。我们的研究结果为探索益生菌增强免疫的机制以及筛选益生菌在水产养殖应用中的最佳施用策略提供了独特的视角。总之，这些结果表明，短期喂养后连续和间断喂养可以在一定程度上增强免疫状态，这可以用作比目鱼健康管理的预防策略。