Distinct microbiome variation in children and adults following RSV infection and its association with host response.

Abstract

Respiratory syncytial virus (RSV) hospitalization rates are higher in children than in adults, which may be related to differences in respiratory microbiota composition. The relationship between differences in the pharyngeal microbiome and the host immune response in adults and children infected with RSV remains unclear. This study aims to investigate changes in the microbiota of RSV-infected adult and pediatric patients receiving inpatient and outpatient care, and to explore their relationship with the host immune response. A total of 223 participants were enrolled in the study, including 30 adult RSV patients, 92 pediatric RSV patients, 51 community-acquired pneumonia (CAP) patients, and 50 healthy controls. Throat swabs were collected for 16S rRNA gene sequencing and transcriptome analysis. We found that the abundance of oral anaerobes (Prevotella and Veillonella) was higher in pediatric inpatients compared to pediatric outpatients. Differences in pharyngeal microbiome composition were observed between pediatric inpatients and outpatients, while not in adult patients. More differentially expressed genes were observed between pediatric inpatients and outpatients than in adults, primarily related to neutrophil chemotaxis and migration pathways. Furthermore, Alphaproteobacteria and Actinobacteria were positively correlated with the expression of CXCL10 and CXCL11 in pediatric inpatients, suggesting a potential link with neutrophil recruitment and inflammatory responses in these patients. Taken together, these findings improve our understanding of the associations between the host transcriptome and microbiome in the context of RSV infection, which may provide insights into factors related to the increased pathogenicity observed in children.