Radwan Mahmoud, Mekky Alsayed E, Moussa Moussa A, Fares Mohamed, Al-Otaibih Wafa Mohammed
Marine Biology Branch, Zoology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt.
Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Nasr City, 11884, Cairo, Egypt.
Fish Shellfish Immunol. 2025 Aug 29;167:110695. doi: 10.1016/j.fsi.2025.110695.
Recently, fermented brown algae have gained interest as a food source due to their high functionality and numerous bioactive components. Therefore, the current study used Lactobacillus plantarum and Saccharomyces cerevisiae probiotics to examine the possible effects of dietary fermented Sargassum muticum (DFSM) on the growth performance of Nile tilapia (Oreochromis niloticus), intestinal health, blood indices, antioxidant levels, and immune response. For 60 days, Nile tilapia (15 fish/aquarium) with an average weight (21.59 ± 1.06 g, four replicates) were fed five isonitrogenous diets that contained 0.0 % (control), 0.5 %, 1 %, 2 %, and 3 % DFSM. The bacterial Aeromonas hydrophila strain was injected intraperitoneally into fish of each treatment following the feeding trial. All growth indices in Nile tilapia were significantly enhanced with a DFSM inclusion above 0.5 %, compared to the control diet. The results displayed that the DFSM in the diet improved fish intestinal health and blood indices, especially in fish fed a diet containing 2 and 3 DFSM %. The fish fed the DFSM displayed a reduced MDA value compared to the control diet and a rise in immunological indices (phagocytic activity and lysozyme) and antioxidants (SOD and CAT), especially at 2 and 3 DFSM % diet. Fish fed 2 and 3 % DFSM diet had significantly upregulated the genes CAT, SOD, GPx, and Nrf2 expression compared to the diet 0.5,1 % and control groups. Conversely, IL-8, IL-1β, and TNF gene expression were upregulated in the control one and downregulated in fish fed a diet containing 2 and 3 DFSM %. The histological analysis revealed that all tissues examined in fish fed DFSM exhibited intact structural improvements as the amount of DFSM supplementation increased. Fish groups fed a diet containing 2 and 3 DFSM % diet exhibited higher survival rates after an A. hydrophila infection challenge than the control group. The study concluded that Nile tilapia requires a 2.5 to 3.0 DFSM% diet to boost growth performance, health status, and infection resistance.
最近，发酵褐藻因其高功能性和众多生物活性成分而作为一种食物来源受到关注。因此，本研究使用植物乳杆菌和酿酒酵母益生菌来检测日粮发酵鼠尾藻（DFSM）对尼罗罗非鱼（奥利亚罗非鱼）生长性能、肠道健康、血液指标、抗氧化水平和免疫反应的可能影响。在60天的时间里，将平均体重为（21.59±1.06克，四个重复）的尼罗罗非鱼（每个水族箱15条鱼）投喂五种等氮日粮，这些日粮分别含有0.0%（对照）、0.5%、1%、2%和3%的DFSM。在饲养试验结束后，将嗜水气单胞菌菌株腹腔注射到各处理组的鱼体内。与对照日粮相比，尼罗罗非鱼中DFSM添加量高于0.5%时，所有生长指标均显著提高。结果表明，日粮中的DFSM改善了鱼的肠道健康和血液指标，特别是在投喂含有2%和3%DFSM日粮的鱼中。与对照日粮相比，投喂DFSM的鱼MDA值降低，免疫指标（吞噬活性和溶菌酶）和抗氧化剂（超氧化物歧化酶和过氧化氢酶）升高，特别是在日粮中DFSM含量为2%和3%时。与日粮0.5%、1%组和对照组相比，投喂2%和3%DFSM日粮的鱼中CAT、SOD、GPx和Nrf2基因表达显著上调。相反，白细胞介素-8、白细胞介素-1β和肿瘤坏死因子基因表达在对照组中上调，而在投喂含有2%和3%DFSM日粮的鱼中下调。组织学分析表明，随着DFSM添加量的增加，投喂DFSM的鱼中所有检测组织的结构均有完整改善。在嗜水气单胞菌感染攻击后，投喂含有2%和3%DFSM日粮的鱼组的存活率高于对照组。该研究得出结论，尼罗罗非鱼需要2.5%至3.0%的DFSM日粮来提高生长性能、健康状况和抗感染能力。
