In this episode of Concentrating on Chromatography, David Oliva and co‑host Candi Gokey sit down with Dr. Pierre‑Hugues (PH) Stefanuto to explore how comprehensive GC×GC‑TOFMS breathomics is reshaping asthma research and personalized medicine. PH shares his journey from forensic applications (yes, even the “smell of death”) to non‑invasive exhaled breath analysis for chronic lung inflammation, and why he believes asthma is the perfect playground to translate breath research into real clinical impact.We dig into PH’s recent work on a complete GC×GC‑TOFMS workflow to improve asthma monitoring, including patient breath collection, VOC analysis, biomarker discovery, and robust data processing strategies. He explains how combining targeted markers like FeNO with VOC “breathprints” can improve asthma phenotyping and treatment decisions, and how his group identified potential VOC biomarkers such as hexane, 1‑propanol, 2‑hexanone, undecane, and nonanal.A major theme of this conversation is PH’s call to “fight the breath proof‑of‑concept paradigm.” Instead of stopping at small, under‑powered studies, his group pushes through large cohorts, rigorous validation, and clinically relevant study design so that breath analysis can actually make it into the clinic and, eventually, into patients’ homes. We also talk candidly about skepticism toward breath analysis, how overpromising has hurt the field, and what it takes to rebuild trust with clinicians and medical staff.We also cover:Why the Multidimensional Chromatography Workshop (MDCW) was designed to be a free, open‑access event, and how that philosophy supports open science, networking, and inclusion of early‑career scientists and lab staff.PH’s path from forensic GC×GC to clinical breathomics and chronic inflammation research, and how CSI‑inspired curiosity turned into a career in analytical chemistry.How untargeted molecular screening and rich VOC fingerprints complement conventional single‑marker tests and enable finer‑grained patient phenotyping.Why GC×GC‑MS often achieves higher annotation rates than LC‑MS in certain metabolomics applications, thanks to retention patterns, EI libraries (NIST/Wiley), and structured 2D chromatography.The future vision: patients blowing into a simple device (or even a phone‑connected system) to monitor lung inflammation at home, integrate with wearables and environmental data, and guide day‑to‑day asthma management.How AI and machine learning can help connect small‑molecule breath data to larger metabolic pathways and multi‑omics datasets, inspired in part by platforms like GNPS.PH’s thoughts on chromatography education, why analytical chemistry is underrepresented in curricula, and how we should prepare the next generation of clinicians and scientists for omics‑driven healthcare.If you’re interested in chromatography, mass spectrometry, breath analysis, asthma, or translational metabolomics, this is a deep yet accessible conversation that bridges instrumentation, statistics, and real‑world clinical needs.Keywords: breathomics, exhaled breath analysis, asthma monitoring, GCxGC, GC×GC‑TOFMS, multidimensional chromatography, volatile organic compounds, VOC biomarkers, untargeted metabolomics, personalized medicine, PH Stefanuto, Pierre‑Hugues Stefanuto, MDCW, Multidimensional Chromatography Workshop, FeNO, chronic lung inflammation, clinical mass spectrometry, analytical chemistry education, chromatography podcast, Concentrating on Chromatography, David Oliva, Candi Gokey