据最新一期《中国渔业统计年鉴》显示，大口黑鲈已成为我国经济鱼类之一。养殖规模不断扩大。过去的研究发现红景天苷具有减少氧化应激和增强免疫的特性。本研究中添加了0、40、80、120、160和200 mg kg-1 6种不同水平的红景天苷补充剂。进行了 56 天的喂养试验，以研究红景天苷对大口黑鲈肠道健康、免疫参数和肠道微生物组成的影响。膳食中添加红景天苷显着影响 Keap-1β/Nrf-2 通路，并显着增加抗氧化酶活性，从而导致大口黑鲈的抗氧化能力显着增加。日粮 SLR 显着降低了饲料系数。发现添加红景天苷的饮食中与紧密连接蛋白相关的基因（Occludin、ZO-1、Claudin-4、Claudin-5）显着上调，表明红景天苷可以改善肠道屏障功能（p < 0.05）。研究发现，通过饮食摄入红景天苷可显着降低肠道肿瘤坏死因子-α (TNF-α) 和白细胞介素-1β (IL-1β) 的转录水平（p < 0.05）。此外，观察到红景天苷可降低肠凋亡因子 Bcl-2 相关死亡启动子 (BAD) 和重组肿瘤蛋白 p53 (P53) 的转录水平 (p < 0.05)。与此同时，SLR12 组中有益细菌梭杆菌和鲸杆菌显着增加，而致病菌变形菌显着减少（p < 0.05）。综上所述，中型大口黑鲈日粮中红景天苷的最佳添加量为120mg/kg-1。版权所有©2024。Elsevier Ltd.出版。

The largemouth bass has become one of the economically fish in China, according to the latest China Fishery Statistical Yearbook. The farming scale is constantly increasing. Salidroside has been found in past studies to have oxidative stress reducing and immune boosting properties. In this study, the addition of six different levels of salidroside supplements were 0、40、80、120、160 and 200 mg kg-1. A 56-day feeding trial was conducted to investigate the effects of salidroside on the intestinal health, immune parameters and intestinal microbiota composition of largemouth bass. Dietary addition of salidroside significantly affected the Keap-1β/Nrf-2 pathway as well as significantly increased antioxidant enzyme activities resulting in a significant increase in antioxidant capacity of largemouth bass. Dietary SLR significantly reduced feed coefficients. The genes related to tight junction proteins (Occludin, ZO-1, Claudin-4, Claudin-5) were found to be significantly upregulated in the diet supplemented with salidroside, indicating that salidroside can improve the intestinal barrier function (p < 0.05). The dietary administration of salidroside was found to significantly reduce the transcription levels of intestinal tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) (p < 0.05). Furthermore, salidroside was observed to reduce the transcription levels of intestinal apoptosis factor Bcl-2 associated death promoter (BAD) and recombinant Tumor Protein p53 (P53) (p < 0.05). Concomitantly, the beneficial bacteria, Fusobacteriota and Cetobacterium, was significantly increased in the SLR12 group, while that of pathogenic bacteria, Proteobacteria, was significantly decreased (p < 0.05). In conclusion, the medium-sized largemouth bass optimal dosage of salidroside in the diet is 120mg/kg-1.Copyright © 2024. Published by Elsevier Ltd.