Breath 2009: International Conference on Breath and Breath Odor Research (26–30 April 2009, Dortmund, Germany)

The conferences of the International Association of Breath Research (IABR) have a tradition going back to 2004 when the the first conference was organized in Dornbirn, Austria. Subsequent conferences have taken place in Innsbruck (2005), Prague (2006), Cleveland (2007) and then in Dortmund in 2009.

The conference in Dortmund was organized sucessfully by Jörg Ingo Baumbach. With around 300 delegates it was also the largest conference in the series of IABR meetings. It was innovative insofar as it was taking place under the auspices of IABR and the International Society for Breath Odor Research (ISBOR). From ongoing cooperation between the two societies, there are now emerging joint projects in overlapping fields of research such as those related to bacteria in the oral cavity.

The Dortmund conference demonstrated that analytical technology for detection of volatile compounds is developing quickly. An example is the use of the time- of-flight (TOF) technique in mass spectrometry, which allows a reduction in measurement time and improvement of the mass resolution. Such developments on the analytical side are of enormous importance as they will push the field forward and will allow the analysis of breath samples with a very high sensitivity and within a few seconds. In addition to higher sensitivity and reduced measurement time, the miniaturization of instruments for clinical application is also showing considerable progress. Tunable lasers or miniaturized ion mobility spectrometers are examples of techniques which will revolutionize the clinical applications of breath research. Whereas in the past, accurate analysis of breath samples could only be done by large research instruments which need analytical expertise, the next few years will bring small instruments which are easily transportable and easily operable. The use of such instruments in clinical practice is not only restricted to medical diagnosis, but will also incorporate therapeutic monitoring even at intensive care units or during surgery.

Another very promising field is the use of isotopically labelled precursors (see the review article by Anil Modak [1]). ¹³C-labelled compounds, for example, can be engineered to end up as ¹³CO₂, which is observed in exhaled breath. The measurement of the ¹³CO₂-content in breath after ingestion of such precursor compounds gives information on the metabolization kinetics of drugs or specific foods. An example would be the tolerance of 5- fluorouracil (5-FU), which is used as a chemotherapeutic. People unable to metabolize 5-FU will also be unable to metabolize ¹³C- labelled uracil, which is now used for the respective breath test. The relevant enzyme dihydropyrimidine dehydrogenase (DPD) is genetically based on transcription of 23 exons. The respective genetic testing would lead to much higher costs than a simple breath test. In addition, the breath test determines the phenotype which sometimes differs from the genotype (due to low expression of the respective gene). With ¹³C-labelled compounds becoming less expensive, such tests can be developed for many different medications and will therefore allow a 'personalized medicine' and personalized medication regimes to become available at reasonable cost.

Another interesting field of research related to breath odor is the investigation of tongue biofilms (see the paper by Benjamin Taylor and John Greenman [2]). Using this technique for simulation of different environments for bacteria (e.g., with different O₂-content) will allow a much better understanding of the bacterial background of malodorous compounds in breath. Also the investigation of saliva (see the paper by M Yoneda et al [3]) gives way to new non-invasive information which complements results achieved through exhaled breath or exhaled breath condensate.

The Journal of Breath Research (JBR) is dedicated to all of these different exciting new developments. JBR is now established as an essential cornerstone in the timely publication of new results in the field and will help in the development of clinically applicable breath tests in the years to come.

References [1] Modak A 2010 Single time point diagnostic breath tests: a review J. Breath Res. 4 017002 [2] Taylor B and Greenman J 2010 Modelling the effects of pH on tongue biofilm using a sorbarod biofilm perfusion system J. Breath Res. 4 017107 [3] Yoneda M, Masuo Y, Suzuki N, Iwamoto T and Hirofuji T 2010 Relationship between the β-galactosidase activity in saliva and parameters associated with oral malodor J. Breath Res. 4 017108