1. Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
2. Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Groningen, the Netherlands
3. Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
4. Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
5. Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Ant. Deusinglaan 1, Groningen, 9713 AV, the Netherlands
6. Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands