Technology: Digging Deeper

Home / Technology: Digging Deeper

The technology behind our medical device identifies changes in nutrient metabolism. The same device uses different algorithms to detect applicable changes in the breath depending on the setting and subject providing the breath samples.

The Canary device utilizes these changes to monitor at risk patients through their infection onset and progression/recovery phases. In these cases, nutrients normally used for physical function or normal growth are diverted to making immune proteins or providing calories for defense activities during the onset and progression of a severe infection. There are two natural phenomenon that cause changes in the carbon isotope ratio during severe infections: the “onset” phase of the immune response (called the acute phase response), and the “progression” phase of the infection. During the “onset” phase cytokines, such as tumor necrosis factor (TNF) and Interleukin-1 beta (IL-1B), are released and signal the body to catabolize (i.e. break down) muscle tissue to free necessary amino acid resources.1,2 These amino acids are used as energy to fuel the immune response or as building blocks for other immune proteins and defense compounds. When an amino acid is used for energy it ultimately is exhaled as CO2. Amino acids are naturally composed of stable isotopes. The carbon-12 isotope is more easily burned as fuel during this response, while the carbon-13 isotope is more likely to be incorporated into immune proteins. The scientific basis for this is called fractionation, the heavier 13C reacts more slowly than 12C, which results in a distinct change in the 13C/12C ratio. During the “progression” phase the breath delta value dramatically increases along with its variance. This is due to reduced availability of oxygen in body tissues and the resulting shift to an anaerobic state that is characterized by a distinct change in the BDV. Thus, the BDV can be thought of as a biomarker for infection.




Similar changes in energy metabolism can be used to monitor energy balance using the SmartBurn technology. In the energy balance setting, the same naturally occurring stable carbon isotope ratios in body proteins, fats and carbohydrates reflect the isotope ratios of the diet consumed.3,4 As macronutrients are metabolized for energy, the carbon structures from the diet are converted to CO2. Typically, the body is oxidizing a mixture of carbohydrate, protein and lipid. During the conversion of glucose to lipids, enzymatic processes discriminate against 13C.5 This results in body lipids being about 3-5‰ lighter than carbohydrates.6 When the ratio of the macronutrient oxidation changes, the relative contribution of the isotopic composition of the exhaled breath will also change. The trend of the breath (also called the Breath Delta Value or BDV) can be utilized to guide workout goals and rest and recovery processes.





1Li Y-P, Chen Y, John J, Moylan J, Jin B, Mann DL, and Reid MB. Tnf-{Alpha} Acts Via P38 Mapk to Stimulate Expression of the Ubiquitin Ligase Atrogin1/Mafbx in Skeletal Muscle. 19(3): p. 362-370 2005.
2 Wray CJ, Mammen JMV, Hershko DD, and Hasselgren P-O. Sepsis Upregulates the Gene Expression of Multiple Ubiquitin Ligases in Skeletal Muscle. 35(5): p. 698 2003.
3 Nakamura K, Schoeller DA, Winkler FJ, Schmidt HL: Geographical variations in the carbon isotope composition of the diet and hair in contemporary man. Biomed Mass Spectrom 1982, 9(9):390-394.
4 O’Connell TC, Hedges RE: Investigations into the effect of diet on modern human hair isotopic values. Am J Phys Anthropol 1999, 108(4):409-425.
5 DeNiro MJ, Epstein S: Mechanism of carbon isotope fractionation associated with lipid synthesis. Science 1977, 197(4300):261-263.
6 Schoeller DA, Brown C, Nakamura K, Nakagawa A, Mazzeo RS, Brooks GA, Budinger TF: Influence of metabolic fuel on the 13C/12C ratio of breath CO2. Biomed Mass Spectrom 1984, 11(11):557-561.