Mogroside V protects lipopolysaccharides-induced lung inflammation chicken via suppressing inflammation mediated by the Th17 through the gut-lung axis

Lipopolysaccharide (LPS) exposure triggers pulmonary inflammation, leading to compromised lung function in broiler. As amplified by policy restrictions on antibiotic usage, seeking antibiotic alternatives has become imperative. Mogroside V (MGV) has been reported to have a beneficial role in livestock and poultry production due to its remarkable antiinflammatory effects. Despite evidence showcasing MGV's efficacy against LPS-triggered lung inflammation, its precise mechanism of action remains elusive. In this study, we transplanted normal fecal microbiota (CF), fecal microbiota modified by MGV (MF), and sterile fecal filtrate (MS) into broiler with LPS-induced pneumonia. The results showed that through fecal microbiota transplantation (FMT), transplanting MGV-induced microbial populations significantly mitigated tissue damage induced by LPS and enhanced the mRNA level of pulmonary tight junction proteins and mucoprotein (P < 0.01). The expression levels of RORα (P < 0.001), Foxp3 (P < 0.01), and PD-L1 (P < 0.01) were significantly increased in the MF group than CF group. The concentrations of IL-6 and IL-17 in broilers lung tissue of MF group were lower than those in broilers of CF group (P < 0.05). Furthermore, the concentration of TGF-β in broilers serum of MS and MF groups was higher than those in broilers of CF group (P < 0.05). Microbial community analysis demonstrated that at genus level, the harmful bacterial populations Escherichia-Shigella and Helicobacter following FMT treatment were significantly reduced in MF group (P < 0.05), potentially mediating its protective effects. Compared with CF group, valerate content and FFAR2 mRNA expression levels in MF group were significantly increased (P < 0.05). The study suggests that MGV via the gut-lung axis, attenuates Th17-mediated inflammation, offering promise as a therapeutic strategy against LPS-induced lung inflammation in chickens.