Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA. Clinical and Translational Epidemiology Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA. Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St Louis, Missouri, USA. Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. Tufts University School of Medicine, Boston, Massachusetts, USA. Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA. Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.