Insights into the role of the respiratory tract microbiome in defense against bacterial pneumonia

• Published in: Current opinion in microbiology Vol. 77; p. 102428
• Main Authors: Drigot, Zoe G, Clark, Sarah E
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2024
• Subjects: Humans; Lung - microbiology; Microbiota; Oropharynx - microbiology; Pneumonia, Bacterial; Respiratory Tract Infections - microbiology
• ISSN: 1369-5274; 1879-0364
• DOI: 10.1016/j.mib.2024.102428

The respiratory tract microbiome (RTM) is a microbial ecosystem inhabiting different niches throughout the airway. A critical role for the RTM in dictating lung infection outcomes is underlined by recent efforts to identify community members benefiting respiratory tract health. Obligate anaerobes common in the oropharynx and lung such as Prevotella and Veillonella are associated with improved pneumonia outcomes and activate several immune defense pathways in the lower airway. Colonizers of the nasal cavity, including Corynebacterium and Dolosigranulum, directly impact the growth and virulence of lung pathogens, aligning with robust clinical correlations between their upper airway abundance and reduced respiratory tract infection risk. Here, we highlight recent work identifying respiratory tract bacteria that promote airway health and resilience against disease, with a focus on lung infections and the underlying mechanisms driving RTM-protective benefits. [Display omitted] •Obligate anaerobes in the lung improve protection against pneumonia.•Gram-positive bacteria in the nasal cavity correlate with reduced infection risk.•Within-genus relatives restrain pathogen virulence and growth.