Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs), Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Front Immunol. 2021 Mar 8;12:640767. doi: 10.3389/fimmu.2021.640767. eCollection 2021.
Marine fish larvae are vulnerable during the early life period. The early intervention using probiotics may be a promising method to improve growth of fish larvae. In this study, a 30-day feeding trial was conducted to evaluate the effects of early life intervention using probiotic (CB) on growth performance, intestinal development, immune response and gut microbiota of large yellow croaker () larvae. Four isonitrogenous and isolipidic diets were formulated with the supplementation of four different levels of CB (5 × 10 CFU g), 0.00% (Control), 0.10% (CB1), 0.20% (CB2), and 0.40% (CB3). Results showed that larvae fed diets with CB had significant higher final length than the control group. Meanwhile, larvae fed the diet with 0.10% CB had significant higher final weight and specific growth rate (SGR) than the control group. However, no significant difference in survival rate was observed among dietary treatments. CB supplementation significantly increased the height of intestinal villus and the length of intestinal enterocyte. Similarly, CB supplementation significantly increased the expression of tight zonula occludens-2 () and ornithine decarboxylase () than the control group. Larvae fed the diet with 0.20% CB had significant higher lipase and leucine-aminopeptidase (LAP) activity than the control group. Moreover, CB supplementation significantly improved immune enzyme activities than the control group. Sequencing of bacterial 16S rRNA V4-5 region indicated that dietary CB altered intestinal microbiota profile and decreased intestinal microbial diversities of larvae. CB supplementation could effectively increase the abundance of CB, and decrease the abundance of some potential pathogenic bacteria in larval gut. These results revealed that early life intervention using 0.10-0.20% CB could promote growth of large yellow croaker larvae probably through promoting intestinal development, improving immune enzyme activities and modulating gut microbiota.
海洋鱼类幼鱼在生命早期很脆弱。早期使用益生菌进行干预可能是改善鱼类幼鱼生长的一种很有前途的方法。本研究进行了为期 30 天的饲养试验，以评估早期使用益生菌（CB）对大黄鱼（）幼鱼生长性能、肠道发育、免疫反应和肠道微生物群的影响。用四种不同水平的 CB（5×10 CFU g）、0.00%（对照）、0.10%（CB1）、0.20%（CB2）和 0.40%（CB3）的四种等氮和等脂饲料配方。结果表明，摄食 CB 饲料的幼鱼终末体长显著高于对照组。同时，摄食 0.10% CB 饲料的幼鱼终末体重和特定生长率（SGR）显著高于对照组。然而，摄食不同饲料处理的幼鱼存活率没有显著差异。CB 补充剂显著增加了肠绒毛的高度和肠上皮细胞的长度。同样，CB 补充剂显著增加了紧密连接蛋白-2（）和鸟氨酸脱羧酶（）的表达，高于对照组。摄食 0.20% CB 饲料的幼鱼的脂肪酶和亮氨酸氨肽酶（LAP）活性显著高于对照组。此外，CB 补充剂显著提高了免疫酶活性，高于对照组。细菌 16S rRNA V4-5 区的测序表明，饲料 CB 改变了肠道微生物群的组成，降低了幼鱼肠道微生物的多样性。CB 补充剂可有效增加 CB 的丰度，并降低幼鱼肠道中一些潜在病原菌的丰度。这些结果表明，早期使用 0.10-0.20% CB 进行生命干预可以促进大黄鱼幼鱼的生长，可能是通过促进肠道发育、提高免疫酶活性和调节肠道微生物群来实现的。
