QingXiaoWuWei decoction alleviates methicillin-resistant Staphylococcus aureus-induced pneumonia in mice by regulating metabolic remodeling and macrophage gene expression network via the microbiota-short-chain fatty acids axis

QingXiaoWuWei decoction (QXWWD) exerts a prominent therapeutic effect on the methicillin-resistant Staphylococcus aureus (MRSA)-induced pneumonia model in mice; however, its pharmacological mechanisms remain unclear. This study aimed to investigate the underlying pharmacological mechanisms of QXWWD in MRSA-induced pneumonia. In the present study, 62 compounds were identified using high-resolution mass spectrometry. Network analysis, leveraging mass spectrometry, pinpointed the infection-linked, immunity-associated, and inflammation-related pathways as predominant targets. QXWWD significantly alleviated MRSA-induced pneumonia in mice and decreased the levels of pro-inflammatory cytokines and chemokines. 16S ribosomal RNA (16S rRNA) sequencing revealed that QXWWD regulated gut microbiota composition in mice with MRSA-induced pneumonia, which correlated with the enrichment of certain short-chain fatty acids (SCFAs)-producing strains. Further analysis with targeted metabolomics confirmed that the acetic, propionic, and butyric acid levels in the mice's serum were elevated significantly after QXWWD treatment. The fecal microbiota transplantation experiment suggested that gut microbiota from QXWWD-treated mice and SCFAs treatment may alleviate MRSA-induced pneumonia. Additionally, the untargeted metabolomic analysis further demonstrated that metabolic remodeling is significantly regulated by the QXWWD, particularly by the enhancement of the citrate cycle. In the case of QXWWD treatment, global transcriptome profiling revealed that genes, such as NLRP12 and CYP1A1, associated with macrophage antibacterial and immune activity, were downregulated. The results revealed that QXWWD regulated metabolic remodeling and macrophage gene expression network via the microbiota-SCFAs axis and thus alleviated MRSA-induced pneumonia in mice. IMPORTANCE Methicillin-resistant Staphylococcus aureus (MRSA) colonizes the upper respiratory airways and is resistant to antibiotics. MRSA is a frequently acquired infection in hospital and community settings, including cases of MRSA-induced pneumonia. Multidrug-resistant Staphylococcus aureus and the limited efficacy of antibiotics necessitate alternative strategies for preventing or treating the infection. QingXiaoWuWei decoction (QXWWD) protects against both gut microbiota dysbiosis and MRSA-induced pneumonia. Furthermore, the QXWWD-regulated metabolic remodeling and macrophage gene expression network contribute to its protective effects through the microbiota-short-chain fatty acid axis. The results of this study suggest that QXWWD and its pharmacodynamic compounds might have the potential to prevent and treat pulmonary infections, especially those caused by multidrug-resistant organisms. Our study provides a theoretical basis for the future treatment of pulmonary infectious diseases by manipulating gut microbiota and their metabolites via traditional Chinese medicine. Methicillin-resistant Staphylococcus aureus (MRSA) colonizes the upper respiratory airways and is resistant to antibiotics. MRSA is a frequently acquired infection in hospital and community settings, including cases of MRSA-induced pneumonia. Multidrug-resistant Staphylococcus aureus and the limited efficacy of antibiotics necessitate alternative strategies for preventing or treating the infection. QingXiaoWuWei decoction (QXWWD) protects against both gut microbiota dysbiosis and MRSA-induced pneumonia. Furthermore, the QXWWD-regulated metabolic remodeling and macrophage gene expression network contribute to its protective effects through the microbiota-short-chain fatty acid axis. The results of this study suggest that QXWWD and its pharmacodynamic compounds might have the potential to prevent and treat pulmonary infections, especially those caused by multidrug-resistant organisms. Our study provides a theoretical basis for the future treatment of pulmonary infectious diseases by manipulating gut microbiota and their metabolites via traditional Chinese medicine.