The intersection between human metapneumovirus and the respiratory microbiome

Human metapneumovirus is one of the viral causes of respiratory illness that can range from mild to life-threatening diseases. In December 2024, there was news about increased cases of human metapneumovirus (HMPV) in China, when 6.2% and 5.4% of positive respiratory illnesses and admissions, respectively, were linked to HMPV, surpassing adenovirus, rhinovirus, and COVID-19. There have been concerns about it becoming another epidemic, and by implication, a pandemic, especially as the world is gradually recovering from COVID-19 and its devastating impacts. Currently, there is no directly acting antiviral drug targeting HMPV, and this has left a gap in its treatment and management, especially in the young, elderly, and immunocompromised, who are prone to having severe manifestations. As the immune system is crucial in fighting and eliminating the infection, modulating the immune system directly or indirectly can treat HMPV. The lung that was initially known to be sterile is now found to house different populations of microorganisms, including bacteriome, virome, and mycobiome. The lung microbiome modulates HMPV infection. The presence of pathobionts like H. influenzae enhances HMPV infection and severity. The detection of the microbiome was made possible by the advent of cutting-edge technologies like next-generation sequencing and bioinformatics tools. The combination of Recombinase Polymerase Assay, CRISPR-Cas12a, and Fluorescence Assay has been used in the rapid detection of HMPV in China. The microbiome plays a crucial role in shaping the immune system. Exploring such can be a way of managing HMPV. Probiotics, prebiotics, and postbiotics are ways in which the microbiota can be manipulated to limit adverse drug reactions. These can be explored in HMPV diagnosis, treatment, and prevention.