Zhou Wei, Xie Mingxu, Xie Yadong, Liang Hui, Li Ming, Ran Chao, Zhou Zhigang
Sino-Norway Joint Lab on Fish Gut Microbiota, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Fish Shellfish Immunol. 2022 May;124:332-342. doi: 10.1016/j.fsi.2022.04.019. Epub 2022 Apr 14.
The purpose of this study was to evaluate the effects of Cetobacterium somerae XMX-1 fermentation product on gut and liver health and resistance against bacterial infection in genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Fingerling GIFTs (n = 120; initial weight 1.33 ± 0.00 g) were randomly assigned to twelve 90-L tanks (four tanks per diet, 10 fish per tank) with three groups: control group (basal high fat diet), 1% XMX-1 group and 2% XMX-1 group (basal diet supplemented with 10 and 20 g XMX-1/kg feed respectively). After 49 days feeding trial, the growth performance and gut and liver health parameters of tilapia were evaluated. Also the gut microbiota and virome were detected by sequencing. 2% XMX-1 fermentation product had no effect on growth performance. For gut health, the expression of hypoxia-inducible factor-lα (Hif-1α) tend to increase in 1% XMX-1 group (P = 0.053). The expression of intestinal interleukin-6 (IL-6) and tumor growth factor β (TGF-β) was significantly down-regulated in 1% and 2% XMX-1 groups (P < 0.05), and the intestinal expression of interleukin-1β (IL-1β) had a trend to decrease (P = 0.08) in 1% XMX-1 group versus control. 1% and 2% XMX-1 groups also increased the intestinal expression of tight junction genes Claudin (P = 0.06 and 0.07, respectively). For liver health, XMX-1 fermentation product significantly decreased liver TAG (P < 0.05). Furthermore, the hepatic expression of lipid synthesis gene fatty acid synthase (FAS) was significantly decreased and the expression of lipid catabolism related-gene uncoupling protein 2 (UCP2) was significantly increased in 1% XMX-1 and 2% XMX-1 groups (P < 0.01). And the hepatic expression of IL-1β and IL-6 significantly decreased in 1% XMX-1 and 2% XMX-1 groups (P < 0.05). XMX-1 fermentation product increased the abundance of Fusobacteria in the gut microbiota and 2% XMX-1 group led to alteration in the virome composition at family level. Lastly, the time of tilapia death post Aeromoans challenge was delayed in 1% XMX-1 and 2% XMX-1 groups compared with control. To sum up, our results show that the dietary supplementation of XMX-1 fermentation product can improve the gut and liver health as well as the resistance against pathogenic bacteria of tilapia.
本研究旨在评估索氏栖热菌XMX - 1发酵产物对遗传改良养殖罗非鱼（吉富品系尼罗罗非鱼）肠道和肝脏健康以及抗细菌感染能力的影响。将吉富品系罗非鱼苗种（n = 120；初始体重1.33±0.00克）随机分配到12个90升的水箱中（每种饲料4个水箱，每个水箱10尾鱼），分为三组：对照组（基础高脂饲料）、1% XMX - 1组和2% XMX - 1组（基础饲料分别添加10克和20克XMX - 1/千克饲料）。经过49天的饲养试验，评估了罗非鱼的生长性能、肠道和肝脏健康参数。同时通过测序检测了肠道微生物群和病毒组。2% XMX - 1发酵产物对生长性能无影响。对于肠道健康，1% XMX - 1组中缺氧诱导因子 - 1α（Hif - 1α）的表达有增加趋势（P = 0.053）。1%和2% XMX - 1组中肠道白细胞介素 - 6（IL - 6）和肿瘤生长因子β（TGF - β）的表达显著下调（P < 0.05），与对照组相比，1% XMX - 1组中白细胞介素 - 1β（IL - 1β）的肠道表达有下降趋势（P = 0.08）。1%和2% XMX - 1组还增加了紧密连接蛋白Claudin的肠道表达（分别为P = 0.06和0.07）。对于肝脏健康，XMX - 1发酵产物显著降低了肝脏甘油三酯（P < 0.05）。此外，1% XMX - 1组和2% XMX - 1组中脂质合成基因脂肪酸合酶（FAS）的肝脏表达显著降低，脂质分解相关基因解偶联蛋白2（UCP2）的表达显著增加（P < 0.01）。1% XMX - 1组和2% XMX - 1组中IL - 1β和IL - 6的肝脏表达也显著降低（P < 0.05）。XMX - 1发酵产物增加了肠道微生物群中梭杆菌的丰度，2% XMX - 1组导致病毒组在科水平上的组成发生改变。最后，与对照组相比，1% XMX - 1组和2% XMX - 1组中罗非鱼在气单胞菌攻击后死亡的时间延迟。综上所述，我们的结果表明，日粮中添加XMX - 1发酵产物可以改善罗非鱼的肠道和肝脏健康以及对病原菌的抵抗力。
