In the study the investigators follow 50 patients with Crohn's Disease, naive to treatment with biologics. Metabolomic profiling will be performed 1 week prior to the treatment with adalimumab and then every 4 weeks for 6 month. In order to be reliable and reproducible, sampling will be performed in the morning after an overnight fasting period. On the days of serum/urine collection the following data will be collected: CBC, ESR, CRP, Calprotectin, ASCA/pANCA, IL-10, TNFα, IFNγ, Crohn's disease Activity Index, present medication and OTC, Dietary and lifestyle history including 24 hour dietary recall, alcohol intake, smoking and exercise.