1. Research Institute for Internal Medicine (T.B.D., A.Y., T.R., J.K.D., P.A., B.H.), Rikshospitalet, Oslo University Hospital, N-0027 Oslo, Norway
2. Departments of Gastroenterology (J.W.H., Z.K.), Aker Hospital, Oslo University Hospital, N-0027 Oslo, Norway
3. Department of Surgery (I.P.G.), Rikshospitalet, Oslo University Hospital, N-0027 Oslo, Norway
4. Department of Pathology (T.H., E.M.L.), Ullevål Hospital, Oslo University Hospital, N-0027 Oslo, Norway
5. Department of Nutrition (B.A., S.M.U., H.I.N.), Institute of Basic Medical Sciences, University of Oslo, Faculty of Medicine, University of Oslo, N-0318 Oslo, Norway
6. Department of Gastroenterology and Hepatology (K.B.), Rikshospitalet, Oslo University Hospital, N-0027 Oslo, Norway
7. Endocrinology (K.B.), Aker Hospital, Oslo University Hospital, N-0027 Oslo, Norway
8. Faculty of Health, Nutrition, and Management (S.M.U.), Akershus University College, N-2001 Lillestrøm, Norway
9. Section of Clinical Immunology and Infectious Diseases (P.A.), Rikshospitalet, Oslo University Hospital, N-0027 Oslo, Norway