Mogroside V ameliorates broiler pulmonary inflammation via modulating lung microbiota and rectifying Th17/Treg dysregulation in lipopolysaccharides-induced lung injury

The dysbiosis of lung microbiota and inflammatory factors play a crucial role in the occur-rence of lipopolysaccharides (LPS)-induced lung injury. Recently, mogroside V (MGV) has received increasing attention due to its potential health benefits in pneumo-nia, but its complex mechanism needs further experi-mental elucidation. In this study, we established an LPS-induced chicken lung injury model to investigate the protective effect of MGV on LPS-induced acute lung injury in broiler and its related mechanisms. A total of 192 one-day-old white-finned broilers were randomly assigned into 4 groups with 6 replicates: 1) control group: basal diet (d 1-44), saline (d 43); 2) LPS group: basal diet (d 1-44), LPS (d 43); 3) MGV group: basal diet + 0.2% MGV (d 1-44), saline (d 43); 4) MGV-LPS group: basal diet + 0.2% MGV (d 1-44), LPS (d 43). The results showed that pathological examination showed that lung tissue inflammation infiltration was reduced after MGV treatment. In addition, MGV can promote the balance of Th17 and Treg cell cytokines, significantly inhibit the expression of proinflammatory cytokines (IL-1b (P < 0.01), IL-6 (P < 0.001), IL-17F (P < 0.05)), and decrease immunosuppressive target expression (PD-L1 (P < 0.01), PD-1 (P < 0.001), RORa (P < 0.001)), activating the immune system. Further-more, 16S rRNA sequencing analysis showed that MGV treatment could increase the abundance of beneficial bacteria in the lung and reduce the abundance of bacte-ria associated with inflammation. Generally, MGV intervention has a preventive effect on the pathological damage induced by lipopolysaccharides. Its mechanism is related to inhibiting the inflammatory response, regu-lating the Th17/Treg balance, and maintaining the sta-bility of lung microbiota.