Xie Mingxu, Hao Qiang, Xia Rui, Olsen Rolf Erik, Ringø Einar, Yang Yalin, Zhang Zhen, Ran Chao, Zhou Zhigang
Sino-Norway Joint Lab on Fish Gut Microbiota, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China.
Norway-China Joint Lab on Fish Gastrointestinal Microbiota, Institute of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
Front Nutr. 2022 Jul 6;9:918327. doi: 10.3389/fnut.2022.918327. eCollection 2022.
High-fat diets (HFD) are harmful to fish health. Probiotics are commonly utilized to improve fish nutrition metabolism, immune response, and health. Nucleic acids of the probiotic bacterium can be hydrolyzed by nuclease to generate nucleotides. The present study aimed to evaluate the effects of stabilized fermentation product of nuclease-treated XMX-1 [XMX-1 (N)] on growth, non-specific immunity, and liver health of zebrafish (). Compared to the HFD group, 100 g/kg XMX-1 (N) significantly increased weight gain and decreased feed conversion ratio (FCR). However, 5 or 10 g/kg XMX-1 (N) had no influence on zebrafish growth. In addition, supplementation of 100 g/kg XMX-1 (N) significantly increased lysozyme activity and total antioxidant capacity in skin mucus, and the expression of inflammation related genes interleukin 1 beta (β), interleukin 10 (), and interleukin 6 () in the gut as well as fatty acid oxidation related genes uncoupling protein 2 () and proliferator-activated receptor γ coactivator 1α (α) in the liver, while decreased the content of hepatic triacylglycerol (TAG) in zebrafish. The gene sequencing, 16S RNA, showed that 100 g/kg XMX-1 (N) enhanced the relative abundance of Firmicutes while lowered Proteobacteria and Actinobacteria. 10 g/kg XMX-1 (N) significantly increased lysozyme activity and complement component 4 (C4) in skin mucus, and intestinal expression of inflammation-related genes. In the 5 g/kg XMX-1 (N) group, however, only an increase in C4 level in skin mucus was observed. Together, these results reveal that dietary supplementation with nuclease-treated XMX-1 (N) has a dose-dependent beneficial effect on fish health.
高脂饮食（HFD）对鱼类健康有害。益生菌通常用于改善鱼类营养代谢、免疫反应和健康状况。益生菌细菌的核酸可被核酸酶水解产生核苷酸。本研究旨在评估经核酸酶处理的XMX-1 [XMX-1 (N)] 稳定发酵产物对斑马鱼生长、非特异性免疫和肝脏健康的影响。与高脂饮食组相比，100 g/kg XMX-1 (N) 显著增加了体重增加并降低了饲料转化率（FCR）。然而，5或10 g/kg XMX-1 (N) 对斑马鱼生长没有影响。此外，补充100 g/kg XMX-1 (N) 显著增加了皮肤黏液中的溶菌酶活性和总抗氧化能力，以及肠道中炎症相关基因白细胞介素1β（β）、白细胞介素10（）和白细胞介素6（）的表达，以及肝脏中脂肪酸氧化相关基因解偶联蛋白2（）和增殖激活受体γ辅激活因子1α（α）的表达，同时降低了斑马鱼肝脏中三酰甘油（TAG）的含量。基因测序16S RNA显示，100 g/kg XMX-1 (N) 提高了厚壁菌门的相对丰度，同时降低了变形菌门和放线菌门的相对丰度。10 g/kg XMX-1 (N) 显著增加了皮肤黏液中的溶菌酶活性和补体成分4（C4），以及肠道中炎症相关基因的表达。然而，在5 g/kg XMX-1 (N) 组中，仅观察到皮肤黏液中C4水平的增加。总之，这些结果表明，日粮中添加经核酸酶处理的XMX-1 (N) 对鱼类健康具有剂量依赖性的有益作用。
