Breath analysis for health monitoring and clinical applications

Breath composition can now be measured in real time, offering a dynamic and noninvasive view of physiological and biochemical processes occurring in the human body. However, despite many decades of research in the field, clinical use of breath analysis remains limited. Within the breath community, there is no consensus on the exact reasons, but the lack of standardised protocols for breath sampling and analysis, the influence of extrinsic and intrinsic confounders as well as misconceptions in appropriately designing and conducting studies are thought to play a major role. Here, we present a snapshot of the research field, starting with the rationale and origins of breath components, followed by a discussion of the state-of-the-art technologies for breath sampling and analysis, and concluding with present clinical applications, limitations and perspectives.