Analysis of lung microbiota in pediatric pneumonia patients using BALF metagenomic next-generation sequencing: A retrospective observational study

The contribution of the lung microbiota to pneumonia in children of varying severity remains poorly understood. This study utilized metagenomic next-generation sequencing (mNGS) technology to elucidate the characteristics of lung microbiota and their association with disease severity. This retrospective study analyzed bronchoalveolar lavage fluid (BALF) mNGS data of 92 children diagnosed with pneumonia between January 2021 and July 2022. A comparative analysis of the lung microbiota was conducted between the severe pneumonia (SP) (n = 44) and non-severe pneumonia (NSP) (n = 48) groups. Compared to conventional microbiological tests (CMT), mNGS had a higher positivity rate in etiology detection (68% vs 100%). In the NSP group, the predominant type of infection was Mycoplasma pneumoniae single infection, whereas in the SP group, the main type involved a combination of M pneumoniae and bacterial infection. The top 3 identified microbial taxa in both the groups were M pneumoniae, Rothia mucilaginosa, and Schaalia odontolyticus. Although there were no significant differences in the α and β diversity of the lung microbiota between the SP and NSP groups, the abundance of M pneumoniae was higher in the SP group (P = .053). Spearman analysis indicated a highly significant positive correlation between the abundance of Prevotella melaninogenica and M pneumoniae (P < .001). Our analysis identified an association between M pneumoniae infections and disease severity. This study provides a foundation for a better understanding of the pathogenesis of pediatric pneumonia and the relationship between microorganisms.