Viruses

A wide variety of viruses make up the virome, the compartment of the microbiome that includes bacteriophages and commensal eukaryotic viruses, as well as common pathogenic viruses such as influenza virus, rhinovirus and RSV. Susceptibility to viruses varies by age, immunocompetence and the presence of underlying respiratory disorders. Viral RTIs may cause dysbiosis of the lung microbiome, and conversely the make-up of the lung microbiome may affect susceptibility to and severity of a viral infection. Bacteriophages play a key role in modulating the bacterial microbiota of the lung and are a potential avenue of therapy for lung infection, especially in the context of antimicrobial resistance. The study of the lung virome and virus–bacteria interactions at the community level remains in its infancy but is an exciting area of future research with the potential for therapeutic benefits in respiratory disease.