Hao Lihong, Cheng Yuanzhi, Su Weifa, Wang Cheng, Lu Zeqing, Jin Mingliang, Wang Fengqin, Wang Yizhen
National Engineering Laboratory of Biological Feed Safety and Pollution Prevention and Control, Key Laboratory of Molecular Nutrition, Ministry of Education, Key Laboratory of Animal Nutrition and Feed, Ministry of Agriculture and Rural Affairs, Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Institute of Feed Science, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
Appl Microbiol Biotechnol. 2021 Feb;105(4):1657-1668. doi: 10.1007/s00253-021-11111-6. Epub 2021 Jan 21.
Lactic acid bacteria (LAB) play a key role in promoting health and preventing diseases because of their beneficial effects, such as antimicrobial activities, modulating immune responses, maintaining the gut epithelial barrier and antioxidant capacity. However, the mechanisms with which LAB relieve oxidative stress and intestinal injury induced by diquat in vivo are poorly understood. In the present study, Pediococcus pentosaceus ZJUAF-4 (LAB, ZJUAF-4), a selected probiotics strain with strong antioxidant capacities, was appointed to evaluate the efficiency against oxidative stress in diquat-induced intestinal injury of mice. Alanine transaminase (ALT) and aspartate aminotransferase (AST) were analyzed to estimate the liver injury. The intestinal permeability was evaluated by 4 kDa fluorescein isothiocyanate (FITC)-dextran (FD4), D-lactate (DLA), and diamine oxidase (DAO) levels. Jejunum reactive oxygen species (ROS) production was examined by dihydroethidium (DHE) staining. Western blotting was used to detect the expression of nuclear factor (erythroid-derived-2)-like 2 (Nrf2) and its downstream genes in jejunum. The gut microbiota was analyzed by high-throughput sequencing method based on the 16S rRNA genes. The results showed that ZJUAF-4 pretreatment was found to protect the intestinal barrier function and maintain intestinal redox homeostasis under diquat stimulation. Moreover, oral administration of ZJUAF-4 increased the expression of Nrf2 and its downstream genes. High-throughput sequencing analysis indicated that ZJUAF-4 contributed to restoring the gut microbiota influenced by diquat. Our results suggested that ZJUAF-4 protected the intestinal barrier from oxidative stress-induced damage by modulating the Nrf2 pathway and gut microbiota, indicating that ZJUAF-4 may have potential applications in preventing and treating oxidative stress-related intestinal diseases. KEY POINTS: • ZJUAF-4 exerted protective effects against diquat-induced intestinal injury. • Activation of Nrf2 and its downstream targets towards oxidative stress. • ZJUAF-4 administration restoring gut microbiota.
乳酸菌（LAB）因其有益作用，如抗菌活性、调节免疫反应、维持肠道上皮屏障和抗氧化能力等，在促进健康和预防疾病方面发挥着关键作用。然而，乳酸菌在体内缓解百草枯诱导的氧化应激和肠道损伤的机制尚不清楚。在本研究中，戊糖片球菌ZJUAF-4（LAB，ZJUAF-4）是一种具有强大抗氧化能力的益生菌菌株，被用于评估其对百草枯诱导的小鼠肠道损伤中氧化应激的缓解效果。分析谷丙转氨酶（ALT）和谷草转氨酶（AST）以评估肝损伤。通过4 kDa异硫氰酸荧光素（FITC）-葡聚糖（FD4）、D-乳酸（DLA）和二胺氧化酶（DAO）水平评估肠道通透性。用二氢乙锭（DHE）染色检测空肠活性氧（ROS）的产生。采用蛋白质免疫印迹法检测空肠中核因子（红系衍生-2）样2（Nrf2）及其下游基因的表达。基于16S rRNA基因，采用高通量测序方法分析肠道微生物群。结果表明，ZJUAF-4预处理可在百草枯刺激下保护肠道屏障功能并维持肠道氧化还原稳态。此外，口服ZJUAF-4可增加Nrf2及其下游基因的表达。高通量测序分析表明，ZJUAF-4有助于恢复受百草枯影响的肠道微生物群。我们的结果表明，ZJUAF-4通过调节Nrf2途径和肠道微生物群保护肠道屏障免受氧化应激诱导的损伤，表明ZJUAF-4在预防和治疗氧化应激相关肠道疾病方面可能具有潜在应用价值。要点：•ZJUAF-4对百草枯诱导的肠道损伤具有保护作用。•Nrf2及其下游靶点对氧化应激的激活作用。•给予ZJUAF-4可恢复肠道微生物群。
