Breathing is a process we do roughly 20,000 times a day. The human breath contains traces of the metabolic processes of the organism: by analysing them it is possible to diagnose a wide range of pathologies of the gastrointestinal and respiratory system. In normal conditions, the exhaled breath is largely composed of nitrogen (up to 99%), oxygen, carbon dioxide, water vapor and inert gases.

The remaining part is composed of volatile and non-volatile compounds. The monitoring of the volatile metabolites allows to reveal more than 3400 different volatile organic compounds (VOC).

The composition of the exhaled breath depends on:

• inhaled air and external factors such as diet, drugs and environmental factors.
• production of metabolic volatile compounds due to metabolic processes.

The aim of the breath analysis is to detect a marker or pattern of markers related to specific diseases and to determine the metabolic processes that can be responsible of the release of specific components in breath.