Breath as a Sample for Disease Detection

Exhaled Breath [EB] contains many molecules, consisting of small inorganic molecules like carbon-monoxide [CO], Nitric Oxide [NO] and variety of volatile organic compounds [VOCs] like acetone, isoprene, ethane, pentane etc. Apart from VOCs, EB also contains certain non- volatile compounds and mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. All these molecules present in the EB can provide valuable information regarding the different biochemical and metabolic processes taking place in human body, hence serving as a source of massive biomarkers. These biomarkers, which can work as a fingerprint of your body, can be used to detect a variety of diseases like cancers, respiratory diseases like COPD, COVID and many more. Exhalome-based technologies are finding their way into medical equipment's front end. Because of their unique biomarker limits of detection even in tiny amounts, these technologies will play an increasingly essential role in driving a whole sector of electronic medical equipment that intersects with large hospitals to better tailor early diagnosis. The added benefits of exploiting Exhaled breath for clinical detection are that it is a non-invasive way of detection, ready availability and early and fast detection.

Breath sample can be of utmost potential for clinical diagnostics point of view. The collection method is very simple, and the biggest advantage of method is the non-invasive nature of sample collection. Another advantage is that patient from any age group ranging from paediatrics to geriatrics can easily provide the sample and the store is renewable. This nature of breath sample makes it very lucrative to be used in the field of diagnosis. It is recommended to use multiple breaths for screening and detection of different components in EB and since it is reproducible in nature, this will help in reliable diagnosis.

Breath can be sampled in 2 ways: Whole breath and alveolar air. Whole breath sample is relatively easy to collect but is more to contamination from the oral cavity. On the other hand, Alveolar air sampling is more reliable because it is concentrated with VOCs and hence can produce more reproducible and reliable results. Alveolar air sample can easily be achieved using a simple capnograph to monitor the expiratory CO 2.

Basically, there are two approaches for breath sample collection: sample for online analysis and sample for offline analysis. The main difference between both the approaches is that offline analysis requires proper collection and storage of samples, whereas the online analysis does not need sample storage because the results are instant.