Zhang Feng-Li, Yang Ya-Lin, Zhang Zhen, Yao Yuan-Yuan, Xia Rui, Gao Chen-Chen, Du Dong-Dong, Hu Juan, Ran Chao, Liu Zhen, Zhou Zhi-Gang
Sino-Norway Fish Gastrointestinal Microbiota Joint Lab, Institute of Feed Research of Chinese Academy of Agricultural Sciences, Beijing, China.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Institute of Feed Research of Chinese Academy of Agricultural Sciences, Beijing, China.
Front Nutr. 2021 Oct 13;8:726108. doi: 10.3389/fnut.2021.726108. eCollection 2021.
Fatty liver and intestinal barrier damage were widespread in most farmed fish, which severely restrict the development of aquaculture. Therefore, there was an urgent need to develop green feed additives to maintain host liver and intestinal health. In this study, a probiotic pili-like protein, Amuc_1100 (AM protein), was anchored to the surface of ZHY1, and the effects of the recombinant bacteria AM-ZHY1 on liver fat accumulation and intestinal health were evaluated. Zebrafish were fed a basal diet, high-fat diet, and high-fat diet with AM-ZHY1 (10 cfu/g) or control bacteria ZHY1 for 4 weeks. Treatment with AM-ZHY1 significantly reduced hepatic steatosis in zebrafish. Quantitative PCR (PCR) detection showed that the expression of the lipogenesis [peroxisome-proliferator-activated receptors (γ), sterol regulatory element-binding proteins-1c (), fatty acid synthase , and acetyl-CoA carboxylase 1 ()] and lipid transport genes ( and ) in the liver were significantly downregulated ( < 0.05), indicating that AM-ZHY1 could reduce liver fat accumulation by inhibiting lipid synthesis and absorption. Moreover, supplementing AM-ZHY1 to a high-fat diet could significantly reduce serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, indicating that liver injury caused by high-fat diets was improved. The expression of tumor necrosis factor () and interleukin () in the liver decreased significantly ( < 0.05), while β and did not change significantly in the AM-ZHY1 group. Compared to the high-fat diet-fed group, the AM-ZHY1 group, but not the ZHY1 group, significantly increased the expression of intestinal tight junction (TJ) proteins (, and ; < 0.05). Compared to the high-fat diet group, the and were significantly reduced and increased in the AM-ZHY1 group, respectively. In conclusion, the recombinant bacteria AM-ZHY1 has the capacity to maintain intestinal health by protecting intestinal integrity and improving intestinal flora structure and improving fatty liver disease by inhibiting lipid synthesis and absorption. This study will lay a foundation for the application of AM protein in improving abnormal fat deposition and restoring the intestinal barrier in fish.
大多数养殖鱼类中普遍存在脂肪肝和肠道屏障损伤，这严重限制了水产养殖业的发展。因此，迫切需要开发绿色饲料添加剂来维持宿主肝脏和肠道健康。在本研究中，一种益生菌菌毛样蛋白Amuc_1100（AM蛋白）被锚定在ZHY1的表面，并评估了重组菌AM-ZHY1对肝脏脂肪积累和肠道健康的影响。将斑马鱼分别投喂基础饲料、高脂饲料以及添加了AM-ZHY1（10 cfu/g）的高脂饲料或对照菌ZHY1，持续4周。用AM-ZHY1处理显著降低了斑马鱼的肝脏脂肪变性。定量PCR检测显示，肝脏中脂肪生成相关基因[过氧化物酶体增殖物激活受体（γ）、固醇调节元件结合蛋白-1c（）、脂肪酸合酶和乙酰辅酶A羧化酶1（）]以及脂质转运基因（和）的表达均显著下调（<0.05），表明AM-ZHY1可通过抑制脂质合成和吸收来减少肝脏脂肪积累。此外，在高脂饲料中添加AM-ZHY1可显著降低血清天冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT）水平，表明高脂饮食引起的肝脏损伤得到改善。肝脏中肿瘤坏死因子（）和白细胞介素（）的表达显著降低（<0.05），而在AM-ZHY1组中β和没有显著变化。与高脂饲料喂养组相比，AM-ZHY1组（而非ZHY1组）显著增加了肠道紧密连接（TJ）蛋白（、和；<0.05）的表达。与高脂饲料组相比，AM-ZHY1组中分别显著降低和升高。总之，重组菌AM-ZHY1具有通过保护肠道完整性、改善肠道菌群结构来维持肠道健康以及通过抑制脂质合成和吸收来改善脂肪肝疾病的能力。本研究将为AM蛋白在改善鱼类异常脂肪沉积和恢复肠道屏障方面的应用奠定基础。
