The great challenge for exhaled breath analysis: embracing complexity, delivering simplicity

Abstract

'Life is not measured by the number of breaths we take, but by the ones we analyze' As the headspace of the blood, our exhaled breath contains a vast array of substances and molecules that hold great promise for monitoring our health and for the diagnosis and management of various lung and systemic diseases. With recent advances in technology, essentially anything in the blood that is potentially volatile or has a volatile metabolite can be measured in exhaled breath. This includes substances we produce endogenously as part of our normal (or disease-related) metabolism whether this is local in the lung or systemic in origin. Since we are constantly inhaling air from our environment as we breathe in the ambient air, exhaled breath can also reflect our environmental exposure(s). Furthermore, our breath contains volatile compounds produced by our 'internal environment': the bacteria in our gut and mouth. Add to all of those volatile byproducts generated from our diet, medications, drugs, or toxins that we are exposed to and you get a very rich matrix that has great potential to revolutionize and personalize medicine. But in order to unlock the great potential of this highly complex resource, we need to find ways to understand its complexity and control or account for the sources of ambiguity.