Guangdong Provincial Water Environment and Aquatic Products Security Engineering Technology Research Center, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong Province, 510222, China.
South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
Fish Shellfish Immunol. 2022 Nov;130:103-113. doi: 10.1016/j.fsi.2022.08.067. Epub 2022 Aug 28.
Alginate oligosaccharide (AOS) is widely used in agriculture because of its many excellent biological properties. However, the possible beneficial effects of AOS and their underlying mechanisms are currently not well known in grass carp (Ctenopharyngodon idellus). Here, grass carp were fed diets supplemented with 5, 10, or 20 g/kg AOS for six weeks. HE and PAS staining showed that the diets of AOS significantly increased the number of goblet cells in the intestinal. According to transcriptome and quantitative real-time PCR (qRT-PCR) data, AOS-supplemented diets activated the expression of fat metabolism-related pathways and genes. The 16S rRNA sequencing results showed that supplementation with AOS affected the distribution and abundance of the gut bacterial assembly. qRT-PCR and activity assays revealed that the AOS diets significantly increased the antioxidant resistance in gut of grass carp, and down-regulated the expression of inflammatory and up-regulated anti-inflammatory cytokines. Finally, the Aeromonas hydrophila infection assay suggested that the mortality in the groups fed dietary AOS was slightly lower than that in the control. Therefore, supplementing the diet of grass carp with an appropriate amount of AOS can improve fat metabolism and immune responses and alter the intestinal bacterial community, which may help to fight bacterial infection.
藻酸盐寡糖（AOS）由于其许多优异的生物特性而被广泛应用于农业。然而，目前对于草鱼（Ctenopharyngodon idellus）而言，AOS 的可能有益作用及其潜在机制尚不清楚。在这里，草鱼被喂食添加了 5、10 或 20 g/kg AOS 的饮食 6 周。HE 和 PAS 染色表明，AOS 饮食显著增加了肠道中的杯状细胞数量。根据转录组和定量实时 PCR（qRT-PCR）数据，AOS 补充饮食激活了与脂肪代谢相关的途径和基因的表达。16S rRNA 测序结果表明，AOS 的补充影响了肠道细菌组合的分布和丰度。qRT-PCR 和活性测定表明，AOS 饮食显著增强了草鱼肠道的抗氧化抗性，并下调了炎症相关基因的表达，上调了抗炎细胞因子的表达。最后，嗜水气单胞菌感染试验表明，喂食 AOS 饮食的草鱼的死亡率略低于对照组。因此，在草鱼的饮食中补充适量的 AOS 可以改善脂肪代谢和免疫反应，并改变肠道细菌群落，这可能有助于对抗细菌感染。
