1. Department of Internal and Integrative Medicine; Kliniken Essen-Mitte; Faculty of Medicine Essen; University of Duisburg-Essen; Essen Germany
2. Australian Research Centre in Complementary and Integrative Medicine (ARCCIM); University of Technology Sydney; Sydney NSW Australia
3. Department of Integrative Gastroenterology; Faculty of Medicine; University of Duisburg-Essen; Essen Germany
4. Institute of Medical Psychology and Behavioral Immunobiology; University Hospital Essen; University of Duisburg-Essen; Essen Germany