1. University Hospital Regensburg Department of Internal Medicine I, Regensburg, Germany
2. Clinic for Internal Medicine I, University Hospital Halle, Halle, Germany
3. University Hospital Aachen Department of Gastroenterology Metabolic Disorders and Intensive Medicine, Aachen, Germany
4. Elisabeth Hospital Essen Clinic of Internal Medicine and Gastroenterology, Essen, Germany
5. Department of Gastroenterology, Rheumatology and Infectiology, Charité Universitätsmedizin Berlin, Berlin, Germany
6. Berlin Institute of Health at Charité, Berlin, Germany