TY - JOUR T1 - Breath analysis for label-free characterisation of airways disease JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.02586-2017 VL - 51 IS - 1 SP - 1702586 AU - Stephen J. Fowler Y1 - 2018/01/01 UR - http://erj.ersjournals.com/content/51/1/1702586.abstract N2 - The appeal of exhaled breath gas as a potential source of novel respiratory biomarkers is clear. It provides an inexhaustible source of a medium that can be sampled noninvasively, and one that has been in direct contact with the organ of interest. Targeting volatile organic compounds (VOCs) allows us to see even deeper: these small molecules diffuse across barriers and hence breath sampling also captures VOCs from the pulmonary interstitium, the circulation and beyond. Whilst analytical chemists, engineers, and a few forward-thinking clinical researchers have been exploring the breath volatilome since the early 1970s, it is only in the last decade or so that clinical interest has really grown [1–6]. There are probably two main reasons for the slow speed of uptake. First, the medium is extremely complex, and the source of VOCs difficult to define. The air we breathe out contains VOCs from three main sources: the external environment (either inhaled or absorbed through the skin or via ingestion) [7, 8], and metabolism both human [9, 10] and non-human (the microbiome) [11, 12]. To further complicate matters these volatiles may interact, and may be themselves utilised in metabolic processes. The second challenge is common to all ’omics research: the lack of external validation needed to give confidence in findings and support clinical effectiveness studies.Potential breath volatile signatures emerge for key clinical characteristics and phenotypes in airways disease http://ow.ly/7HzJ30hoCIJ ER -