Role of Upper Respiratory Microbiota and Virome in Childhood Rhinitis and Wheeze: Collegium Internationale Allergologicum Update 2021.

There is emerging evidence that the respiratory microbiota influences airway health, and there has been intense research interest in its role in respiratory infections and allergic airway disorders. This review aims to summarize current knowledge of nasal microbiome and virome and their associations with childhood rhinitis and wheeze. The healthy infant nasal microbiome is dominated by Corynebacteriaceae and Staphylococcaceae. In contrast, infants who subsequently develop respiratory disorders are depleted of these microbes and are instead enriched with Proteobacteria spp. Although human rhinovirus and human respiratory syncytial virus are well-documented major viral pathogens that trigger rhinitis and wheezing disorders in infants, recent limited data indicate that bacteriophages may have a role in respiratory health. Future work investigating the interplay between commensal microbiota, virome, and host immunological responses is an important step toward understanding the dynamics of the nasal community in order to develop a strategical approach to combat these common childhood respiratory disorders.