Program and book of abstracts 1st conference

October 17 th – 20 th , 2022, Congress Centre of Slovak Academy of Sciences, Smolenice castle, Slovakia

Fadeev Nikita

Fadeev Nikita is graduate student in Bauman MSTU, Biomedical technologies. Research interests include calibration devices and methods for medical breath tests. VALIDATION METHANE AND HYDROGEN PORTABLE BREATH ANALYZER AIRE2 THROUGH CALIBRATION GASES

N.I. Fadeev 1 , V.V. Krivetsky 2 , O. S. Medvedev 2 1 Bauman Moscow State Technical University (BMSTU, Bauman MSTU) , Moscow, Russia, 2 Lomonosov Moscow State University, Moscow, Russia. BACKGROUND: Hydrogen (H2) and methane (CH4) are produced exclusively by the gut microbiota as a result of food fibers fermentation. Concentrations of these gases in human breath reflect their levels in the gut and could be measured in order to evaluate the fermentation activity. It is well known that at the phase one H2 is produced by hydrogenic bacteria and then (phase two) CH4 could be produced by Archeae methanogens in case their existence in the gut. 4 molecules of H2 are needed for synthesis of 1 molecule of CH4. We assume that the correct fermentation rate could be defined as the total amount of H2 produced during phase one. The total amount of H2 produced could be calculated as the sum of H2 + 4 CH4 in the breath air. OBJECTIVES: There is a new portable analyzer AIRE2 (FoodMarble, Ireland) proposed for evaluation the fermentation activity of the gut microbiota by assessment the H2 and CH4 breath levels, but the vendor does not provide information on technical characteristics of the device, the algorithm for fermentation “Score” calculation, therefore it is not clear whether the measurements are correct and adequate. We did not find publications on the AIRE2 validation. The purpose of this study was to validate¬ four AIRE2 devices using calibration H2 and CH4 gas mixes imitating their levels in human breath. METHODS: Different gas concentrations of H2 and CH4 in the dry and 60% humidity air were produced by the gas flow mixing set-up. H2 (16, 27 and 81 ppm) and CH4 (11, 55 and 110 ppm) concentrations were used separately and in different combinations. Error of gas concentrations was checked by the GastroCH4eck breath monitor (Bedfont®, UK) and was within +/- 5%. 4 AIRE2 devices were calibrated in parallel using Bluetooth connected 3 iPhone and 1 Android smartphones with the mobile applications installed from the vendor’s site (www.foodmarble.com). All measurements were repeated 5 times for each gas mix. Result of each measurement was displayed on the smartphone as fermentation rate in proprietary units (“Score” from 1 to 10). RESULTS: Calibration of the 4 AIRE2 devices have shown better linearity of the fermentation “Scores” depended on the H2 concentrations then depended on the CH4 concentrations. Results obtained show higher sensitivity of the device to the level of H2 vs levels of CH4. For example, the fermentation “Score” was 5.5+/- 1.4 units in response to the H2 (27 ppm) and only 2.0 +/-0.97 units when calibrated with the CH4 (55 ppm). The underestimation of

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