Bacillus velezensis Alleviates LPS-Induced Pulmonary Inflammation in Broilers

In this experiment, Bacillus velezensis and lipopolysaccharide (LPS) were administered via intratracheal instillation in broilers. The results demonstrated that LPS induced severe pulmonary and systemic inflammatory responses. However, after Bacillus velezensis perfusion, the levels of inflammatory factors and oxidative stress in bronchoalveolar lavage fluid (BALF) and serum were significantly reduced. Transcriptomic analysis revealed the activation of genes associated with the peroxisome proliferator-activated receptor (PPAR) pathway in the broilers' lungs. Combined with molecular experiments, it was further confirmed that the level of PPAR-gamma in the lungs was increased, while the level of nuclear factor-kappa B p65 (NF-kappa B p65) was significantly decreased.The experiment also found that Bacillus velezensis enhanced the level of isoflavones in the lungs by increasing the abundance of rare microbial communities. This, in turn, activated the PPAR pathway and inhibited the NF-kappa B pathway, ultimately alleviating pulmonary inflammation.In conclusion, the findings of this experiment provide a novel approach to addressing challenges in the large-scale broiler farming industry.本实验采用气管内滴注法，向肉鸡体内递送贝莱斯芽孢杆菌(Bacillus velezensis)与脂多糖(LPS)。结果显示，LPS可诱发严重的肺部及全身性炎症反应。经贝莱斯芽孢杆菌灌注处理后，肉鸡支气管肺泡灌洗液(BALF)与血清中的炎症因子水平及氧化应激程度均显著降低。转录组学分析表明，肉鸡肺组织中过氧化物酶体增殖物激活受体(PPAR)通路相关基因被激活。结合分子实验进一步证实，肺组织中PPAR-γ的表达水平升高，而核因子κB p65(NF-κB p65)的表达水平显著下调。 本实验还发现，贝莱斯芽孢杆菌可通过提升稀有微生物群落的丰度，增加肉鸡肺组织内异黄酮的含量，进而激活PPAR通路并抑制NF-κB通路，最终缓解肺部炎症。 综上，本实验的研究结果为肉鸡规模化养殖业面临的相关挑战提供了全新思路。