1. Crohn Colitis Center Rhein-Main, 60594 Frankfurt/Main, Germany
2. Institute of Nutritional Science, University of Giessen, 35392 Giessen, Germany
3. St. Elisabethen Krankenhaus, 60487 Frankfurt/Main, Germany
4. Krankenhaus Sachsenhausen, Teaching Hospital of the J. W. von Goethe University Frankfurt/Main, 60594 Frankfurt/Main, Germany
5. Vifor Pharma Deutschland GmbH, 81379 Munich, Germany
6. Department of Gastroenterology and Nutritional Medicine, Krankenhaus Sachsenhausen, Teaching Hospital of the J. W. von Goethe University Frankfurt/Main, 60594 Frankfurt/Main, Germany