The invention relates to a
system for measuring a level of a subject's immune activity (10), the
system comprising: - an
exhaled air sensor (20), - a device for measuring
exhaled air (30), - computation means (40) suitable for determining data relating to the air exhaled by the subject from the measurements carried out by the device (30), - a memory (60) suitable for storing the measurements performed by the device (30) and / or the data calculated by the means (40), and the subject's personal data, - a computation means (70) suitable for determining a level of the subject's immune activity on the basis of at least one item of
exhaled air data, generated in real time by the means (40) and / or stored in the memory (60), - a communication and management interface (80) suitable for presenting said level of the subject's immune activity and / or sub-scores of immunological activity, inflammatory activity, digestive
inflammation and / or
pulmonary inflammation.