Host epithelial cells and upper respiratory tract microbiome

The host epithelial cells and upper respiratory tract (URT) microbiome represent a complex, multi-kingdom ecosystem that serves as the primary defense barrier against inhaled pathogens and environmental stressors. The respiratory epithelium provides a physical shield and produces mucus, while the resident microbiome—comprising bacteria such as Staphylococcus and Corynebacterium—competes with pathogens for nutrients and space (Nature Reviews Microbiology, 2017). This interaction is critical for immune system "priming," where commensal microbes influence the maturation and responsiveness of local immune cells (Frontiers in Cellular and Infection Microbiology, 2021). Dysregulation of this system, often characterized by a loss of microbial diversity or epithelial barrier breach, is a hallmark of diseases like chronic rhinosinusitis, asthma, and increased susceptibility to viral infections like influenza (Journal of Allergy and Clinical Immunology, 2020). While not a single molecular target, the URT environment is the site of action for numerous drugs, including antibiotics that clear infections and corticosteroids that reduce epithelial inflammation (The Lancet Respiratory Medicine, 2019). Understanding the cross-talk between host cells and the microbiome is essential for developing next-generation "microbiome-sparing" therapies or probiotics designed to restore respiratory health.

Other names

Respiratory mucosaNasopharyngeal microbiomeAirway epithelium-microbiota axisUpper respiratory tract (URT) niche

Therapeutic interventions targeting this system function by eliminating pathogenic organisms, suppressing epithelial inflammation, or attempting to restore the commensal microbial community to enhance barrier function and immune homeostasis.