Study on the correlation between respiratory microbiome alterations and disease location/severity in children with Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae pneumonia (MPP) is a common form of community-acquired pneumonia in children, potentially involving multiple organ systems. Accumulating evidence suggests that dysbiosis of the respiratory microbiota is associated with various respiratory diseases. Nevertheless, it remains unclear how the respiratory microbiota varies across anatomical sites, interacts with other microbes, and correlates with host immunity in children with MPP compared to non‑MPP respiratory diseases. In this study, we collected and analyzed pharyngeal swabs, sputum, and bronchoalveolar lavage fluid samples from 401 pediatric MPP patients and 287 control subjects (MPP-negative children with other respiratory conditions).Comparative analysis revealed significant respiratory microbiome dysbiosis in MPP patients, with Mycoplasmoides constituting 30.33% of the total microbial community. A discriminative model based on Mycoplasmoides abundance demonstrated excellent performance (AUC = 0.983, sensitivity = 95.3%, specificity = 98.3%). Notably, Mycoplasmoides abundance showed significant negative correlations with Prevotella, Veillonella_A, Staphylococcus, and Rothia, suggesting potential inhibitory effects.Anatomical distribution analysis indicated distinct microbial distributions: Prevotella and Veillonella_A were predominantly enriched in the upper respiratory tract, while Mycoplasmoides showed greater abundance in the lower respiratory tract. Consistency analysis supported the hypothesis of microbial translocation from upper to lower respiratory tract in affected children.Severe MPP cases exhibited significantly higher Mycoplasmoides abundance. For correlations with clinical indicators, both Mycoplasmoides and Streptococcus showed nominal associations. Our findings elucidate the complex interplay between respiratory microbiota in pediatric MPP patients and its association with disease severity and clinical outcomes. This study highlights the need for further research to explore and validate the prognostic relevance of value of these microbial markers.