Investigation of the Influence of the Human Microbiome on Giant Cell Arteritis

Inclusion Criteria: • Diagnosis of Giant cell arteritis (only in one arm) Exclusion Criteria: * chronic infection (viral, fungi, bacteria) including human immunodeficiency viruses, Hepatitis B/C * acute infection with usage of antibiotics less then 90 days before screening * major gastro-intestinal surgery \<5 years from screening * gastro-intestinal bleeding \<90 days before screening * inflammatory bowel disease (confirmed bioptically) * bulimia or anorexia nervosa * adipositas (body mass index ≥ 40) * intake of high dosage of probiotics (\>10\^9 colony forming units per day) \<90 days before screening * not controlled Diabetes mellitus * Malignancy within one year (except for squamous skin - and basal skin carcinoma without metastasis, cervix carcinoma with curative surgery, Cutaneous T-cell lymphoma) * known abuse of alcohol oder drugs.