Task 1.1 - Cohort recruitment (m1-18): Healthy subjects and patients with asthma will be invited to participate, following ethical approval of the protocol and will be characterised using questionnaires and physiological measurements including lung function, inflammation, responsiveness and immune status. Subjects will be instructed about study procedures, monitoring apps and sampling. Baseline samples will be obtained for metagenomic analysis (T3.1), host status (WP2), bacterial cultures and phage isolation (T4.1).

Task 1.2 - Cohort follow up (m7-36): Subjects will be prospectively followed-up for up to a year. Symptom activity will be monitored using mobile technology (Milestone 1). Regular pre-scheduled visits, as well as unplanned visits in case of a respiratory event, will be performed, during which respiratory samples will be obtained and exposures registered. Samples will be provided to T2.1, T2.2, T3.1.

Task 1.3 - Dysbiosis phenotypes (m31-42): Prospective data of disease activity and exposures from T1.2 will be merged into a common database with trajectories from the same subjects obtained from the metagenome metadata of T3.2 and host responses (T2.1, 2.2). Unsupervised analyses will be used to identify asthma clusters characterised by distinct patterns of microbiome/immunological configurations. NKUA and MUL will equally contribute to the WP1 Tasks