Daniela Polag at BBCon 2024

What does breath methane tell us?

 

00:00  –  Introductions
00:58  –  Presentation ‘What Does Breath Methane Tell Us?’
No live Q&A – please contact us for more information

Talk Abstract:

Methane (CH4), the simplest carbon-based volatile organic compound, is a common constituent of exhaled breath, typically ranging from 20 parts per billion by volume to 40 parts per million (ppmv) above atmospheric background values (around 2 ppmv). Breath CH4 has long been associated exclusively with anaerobic microbial activity (methanogenesis) in the gastrointestinal tract and is thought to be primarily related to intestinal motility. In recent years, our comprehensive high-resolution and high-precision studies of breath CH4, including stable carbon and hydrogen isotope measurements (δ13C-CH4 and δ2H-CH4 values) have broadened the picture of breath CH4 formation. Analytical techniques include gas chromatography equipped with a flame-ionization detector or, isotope ratio mass spectrometer, or optical methods such as cavity ring down spectroscopy.

In a cross-sectional study, we found that the dominant factor of high breath CH4 (> 4 ppmv) is age, or rather age-related changes in human physiology which needs to be considered as a confounding factor in potential CH4 diagnostics. A long-term longitudinal study of individuals who experienced immunological events during the measurement period (i.e., infections, inflammation, induced perturbation by vaccination) showed that CH4 dynamics (temporal increase or decrease in breath CH4 production) are closely related to immune reactions. Isotopic patterns of δ13C-CH4 and δ2H-CH4 values and the application of stable isotope tracing techniques served as a proof of concept for CH4 degradation and the cellular CH4 formation via a radical-driven process, respectively. Our observations imply that non-invasive breath CH4 measurements have the potential to be applied as a biomarker for oxidative-reductive stress reactions.

However, additional investigations are required to obtain unambiguous evidence of non-microbial CH4 formation in humans and the underlying processes of its generation. This will be a significant challenge because in the case of high emitters—where CH4 formation by methanogens is the dominant process—it is difficult to distinguish between the non-microbial and microbial pathways of CH4 production.

Although the biochemical pathways of CH4 formation and degradation are not yet fully understood, frequent monitoring of breath CH4 levels may be used to detect significant changes in ROS levels and oxidative stress, and could potentially be used as an additional diagnostic tool in the field of system biology and precision medicine.

 

Speaker Biography:

Dr. Daniela Polag has been a Research Associate in the Biogeochemistry research group at the Institute of Earth Sciences, Heidelberg University, since 2014. Her academic journey began with a Diploma in Geophysics from Johann-Wolfgang-Goethe-University in Frankfurt, completed between 1996 and 2001. She then served as a Scientific Associate at the Institute of Applied Geophysics, Technical University Berlin, from 2003 to 2006. Dr. Polag then pursued her PhD as part of the ‘Radiometry’ research group under the Heidelberger Academy of Sciences at the Institute of Environmental Physics, Heidelberg University, from 2006 to 2009. From 2010 to 2013, she was a Research Associate with the ‘ORCAS’ research group at the Max-Planck-Institut for Chemistry in Mainz.

Dr. Polag’s research is centered on the energetic use of CO2 to enhance methane yield during biogas production from sewage sludge and renewable energy crops. Her expertise includes stable carbon isotope analysis during anaerobic digestion, isotope labeling experiments, online monitoring of δ13C in methane and CO2 using laser absorption spectrography, and breath CH4 research.

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