Yang Zhe, Sun Gege, Tao Jinsheng, Tang Weirong, Li Wenpei, Wei Zehong, Yu Qifang
State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China.
Yuelushan Laboratory, Changsha 410128, China.
Animals (Basel). 2025 Jul 5;15(13):1983. doi: 10.3390/ani15131983.
This study systematically investigated the effects of dietary tea polyphenols (TPs, major bioactive polyphenols from with potent antioxidant and anti-inflammatory properties) on the growth performance and intestinal health of hybrid crucian carp HCC2 under chronic crowding stress. A low-density control group (44.4 fish/m, basal diet without TPs) and four high-density crowding stress groups (222.2 fish/m) were established, one fed the basal diet without TPs (CS) and three fed basal diets supplemented with 100 (CSLTP), 200 (CSMTP), or 400 (CSHTP) mg/kg TPs. We analyzed the impacts of TPs on growth performance, serum biochemical parameters, antioxidant capacity, expression of lipid metabolism-related genes, and intestinal microbiota composition. The results demonstrated that chronic crowding stress significantly suppressed the final body weight, weight gain rate, and specific growth rate of HCC2, while increasing serum lactate LDH, TG, and ALB and decreasing GLU, LDL-C, ALT, AST, and ALP levels. Dietary TPs supplementation enhanced antioxidant capacity (T-AOC, SOD, CAT, and GSH) and alleviated lipid metabolic disorders by activating the Nrf2/Keap1 and PPARα signaling pathways, thereby upregulating the expression of liver antioxidant genes ( and ) and fatty acid oxidation genes ( and ). Furthermore, intestinal microbiota analysis revealed that chronic crowding stress significantly increased the abundance of Proteobacteria and decreased the proportion of compared to the low-density control. Dietary TPs intervention, particularly at higher doses, partially restored the abundance and reduced the enrichment of potential pathogenic bacteria associated with stress. This study is the first to comprehensively elucidate the mechanism by which TPs alleviate crowding stress through enhanced antioxidant capacity, metabolic regulation, and microbiota remodeling, providing robust theoretical support for the application of plant-based additives in aquaculture.
本研究系统地探究了膳食茶多酚（TPs，茶叶中主要的具有强大抗氧化和抗炎特性的生物活性多酚）对慢性拥挤应激下杂交鲫鱼HCC2生长性能和肠道健康的影响。设立了一个低密度对照组（44.4尾鱼/立方米，基础日粮不含TPs）和四个高密度拥挤应激组（222.2尾鱼/立方米），其中一组投喂不含TPs的基础日粮（CS），另外三组分别投喂添加了100（CSLTP）、200（CSMTP）或400（CSHTP）毫克/千克TPs的基础日粮。我们分析了TPs对生长性能、血清生化参数、抗氧化能力、脂质代谢相关基因表达以及肠道微生物群组成的影响。结果表明，慢性拥挤应激显著抑制了HCC2的终末体重、增重率和特定生长率，同时提高了血清乳酸脱氢酶（LDH）、甘油三酯（TG）和白蛋白（ALB）水平，降低了血糖（GLU）、低密度脂蛋白胆固醇（LDL-C）、谷丙转氨酶（ALT）、谷草转氨酶（AST）和碱性磷酸酶（ALP）水平。日粮中添加TPs可增强抗氧化能力（总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽（GSH）），并通过激活核因子E2相关因子2（Nrf2）/ Kelch样环氧氯丙烷相关蛋白1（Keap1）和过氧化物酶体增殖物激活受体α（PPARα）信号通路缓解脂质代谢紊乱，从而上调肝脏抗氧化基因（和）以及脂肪酸氧化基因（和）的表达。此外，肠道微生物群分析显示，与低密度对照组相比，慢性拥挤应激显著增加了变形菌门的丰度，降低了的比例。日粮TPs干预，尤其是高剂量干预，部分恢复了的丰度，并减少了与应激相关的潜在病原菌的富集。本研究首次全面阐明了TPs通过增强抗氧化能力、代谢调节和微生物群重塑来缓解拥挤应激的机制，为植物性添加剂在水产养殖中的应用提供了有力的理论支持。
