Harnessing breath biomarkers for pneumonia diagnosis and prognosis

Pneumonia is a major cause of death and disability worldwide. A host of pathogens causes pneumonia, and pneumonia presents with a remarkable heterogeneity of clinical symptoms and signs and has varied outcomes. Current approaches to pneumonia diagnosis and risk stratification lack precision such that there is no universally agreed upon biomarker or scoring system. These limitations have prompted calls for novel, noninvasive, and more precise approaches to better diagnosing pneumonia and predicting outcomes.

We performed a comprehensive literature search through PubMed to identify studies reporting on breath biomarkers in pneumonia published up to 31 July 2025. This manuscript explores breath-based metabolomics as a novel approach to biomarker development in pneumonia. It describes breath collection methods, including devices available and types of breath samples for analysis. It reviews the potential role of exhaled breath analysis to expedite pneumonia diagnosis, monitor response to therapy, and predict clinical trajectory.

Breath-based metabolomics could improve the recognition and management of pneumonia. It is a noninvasive, potentially continuous method that provides a direct window into the lung for novel insights into the underlying biology of pneumonia.