Chronic hypoxia is a common environmental stress factor in aquaculture. Many researchers have illustrated the physiological and metabolic changes under chronic hypoxia, but there are few studies to evaluate the relationship between dietary nutrients and hypoxic adaptation in fish. In the present study, we fed zebrafish with control diet (C), high-carbohydrate diet (HC), high-fat diet (HF) and high-protein diet (HP) at normal dissolved oxygen (DO = 7.0 ± 0.5 mg/L) or low dissolved oxygen (DO = 2.5 ± 0.5 mg/L) environment, respectively. After a 7-week feeding trial, the growth performance, body composition, tissue biochemical indexes, mRNA expressions of hifα isoforms and nutrient metabolism-related genes, intestinal digestive enzyme activities and microbiota composition were measured. The results indicated that only the HP diet could alleviate the reduction of body weight and feed efficiency induced by chronic hypoxia, but the HF diet feeding worsened the adverse effects of chronic hypoxia in zebrafish. At the C groups, hypoxia increased catabolism of lipid and protein, but at the HP groups, hypoxia enhanced utilization of glycogen and protein. Compared to the C-hypoxia group, the HP feeding could activate transcription of hif-1a and its downstream glycolysis genes in chronic hypoxia. Furthermore, at hypoxic state, the HP feeding could alleviate the reduction of intestinal digestive enzyme activities and microbiota dysbiosis induced by the chronic hypoxia, including increasing bacterial diversity and decreasing Cetobacterium genus abundance. This is the first study indicating that high protein intake could strengthen ability of fish in resisting the negative effect of chronic hypoxia.

慢性缺氧是水产养殖中常见的环境压力因素。许多研究人员已经说明了慢性低氧条件下的生理和代谢变化，但是很少有研究评估饮食营养与鱼类低氧适应之间的关系。在本研究中，我们以正常溶解氧（DO = 7.0±0.5 mg / kg）给斑马鱼饲喂对照饮食（C），高碳水化合物饮食（HC），高脂饮食（HF）和高蛋白饮食（HP）。 L）或低溶解氧（DO = 2.5±0.5 mg / L）环境。经过7周的喂养试验，hifα的生长性能，身体组成，组织生化指标，mRNA表达测量同工型和营养代谢相关基因，肠道消化酶活性和微生物群组成。结果表明，仅HP饮食可以减轻慢性缺氧引起的体重降低和饲料效率降低，而HF饮食喂养则加剧了斑马鱼慢性缺氧的不利影响。在C组，低氧增加了脂质和蛋白质的分解代谢，但是在HP组，低氧增加了糖原和蛋白质的利用。与C-低氧组相比，HP喂养可以激活hif-1a的转录及其下游糖酵解基因在慢性缺氧中的作用。此外，在缺氧状态下，HP喂养可以减轻由慢性缺氧引起的肠道消化酶活性的降低和微生物群的营养不良，包括增加细菌多样性和减少杆菌属的丰度。这是第一项表明高蛋白质摄入量可以增强鱼类抵抗慢性缺氧负面影响的能力的研究。