Vancomycin Protects Against Lung Injury and Promotes Butyrate Metabolism

Lung injury is one of the most common clinical respiratory diseases, caused by the exposure of lung tissue to various stimuli (including hypoxia, ischemia-reperfusion, and foreign substances). Among them, chronic lung injury is characterized by continuous inflammation in the lungs, which damages the endothelial and epithelial cell barriers within the lungs. Clinically, it presents as severe hypoxia and diffuse functional impairment, and on imaging, it shows diffuse alveolar damage, accompanied by varying degrees of inflammation and airway obstruction. Several studies have highlighted the role of gut microbiota in modulating immune responses and pathological features of respiratory diseases through the gut-lung axis. However, the precise metabolic mechanism remains unknown. A lung injury model was generated by transplanting microbiota from acute lung injury (ALI) patients into healthy C57BL/6J mice. The changes in the gut microbiota and metabolic phenotypes of the feces samples from ALI patients and lung-injured mice were analyzed using 16S rRNA sequencing technology and metabolomics based on ¹H-nuclear magnetic resonance (¹H-NMR), respectively. The effect of gut microbiota on lung injury was also explored after giving an oral vancomycin treatment to lung-injury mice. The data presented here show that Firmicutes formed the vital species of microbiota that was different in lung-injury mice. Moreover, butyrate (produced by Firmicutes) was the most crucial metabolite in the feces samples of ALI patients and lung-injury mice. ELISA and Hematoxylin-Eosin results showed aggravated functional disturbances in the intestinal barrier of ALI patients and lung inflammation in the lung-injured mice. These phenomena were significantly alleviated after the oral administration of vancomycin. Besides, the utilization of butyrate in the colon of mice was increased considerably. Thus, vancomycin can affect the metabolism of butyrate in the colon by influencing the intestinal microbiota, and it can help in the treatment of lung injury.