The investigators perform a longitudinal prospective multi-center study for ulcerative colitis (UC) patients with a flare at/and after the time of starting a new treatment and healthy household controls. They will perform intense longitudinal bio-sampling and deep clinical characterization.~With this information the aim is to develop a predictive signature regarding the success of a new ly started anti-inflammatory therapy after an UC flare.
The primary goal of the study is to develop an early (within 4 weeks) combined microbiota/metabolic signature predicting clinical response upon anti-inflammatory treatment in UC patients.