T. Villinger, Argos Messtechnik GmbH
11 May 2020
Personalized nutrition is based on specific information about the person the nutrition is for. This specific information may include data which can easily be recorded such as e.g. weight and size, but could include other data, which are more specific to the person, such as information about genetics or biome. This information could include data about body fluids (e.g. blood and urine), but also information about specific components in the person's exhaled breath. Information which is specific of some biological state or condition is called biomarker. Use of biomarkers from body fluids is very common; however analysis of breath which is performed non-invasively is not yet commonly used. One goal of the Nutrishield project is to demonstrate that novel photonics analyzers can be used to analyze breath. Another one is to make use of the knowledge about changes of these biomarkers for composing personalized nutrition.
Exhaled breath consists of hundreds of gaseous compounds, including inorganic compounds (e.g., ammonia, nitric oxide, hydrogen sulfide) and volatile organic compounds (VOCs), arising from the person’s normal body metabolism. Endogenous emissions reflect changes in the internal metabolism when illnesses occur, but can also vary in response to various (external) stimuli. Many exhaled compounds potentially reflect the physiological and pathophysiological conditions related to various diseases, but only some VOCs have been established as biomarkers. Within this project we shall focus on the detection of gaseous compounds which are depending on the colonic fermentation and the activity/presence of bacteria and other microorganisms in the guts. Diet, as well as low/ high nutritional status have a strong influence on the activity of these microorganisms and subsequently, on the concentrations of the metabolites produced.
Analysis of breath:
The person, whose breath is to be analyzed, breathes into the device. Breath containing the biomarkers is passed to a gas cell inside the device. Laser radiation (see blog contribution from ALPES) with specific wavelength passes through the gas cell. The concentration of the biomarkers of interest in the breath contained in the gas cell is analyzed by molecular spectroscopy at distinct band positions of the biomarkers. This analysis requires well defined laser lines.
The radiation emitted by the lasers interacts with the biomarkers to be analyzed. The biomarkers absorb some radiation which reduces the intensity of the laser lines. The reduced intensity of the laser radiation is detected by photodiodes. The reduction in signal is a measure of the concentration of the biomarkers.
In contrary to the analysis of body fluids, which are usually sent to a lab for analysis, breath samples can be analyzed online. The analytics of the exhaled breath is performed instantly i.e. without the time delay which is usually necessary when the samples are analyzed in a lab. Thus, the concentration of the biomarkers in exhaled breath will be available within a few minutes whilst the analysis is performed non-invasively.
Figure 1: Commercial breath analyzer from ArgosMED for evaluating the metabolic capacity of the liver.