1. Division of Digestive Diseases and Nutrition, University of Kentucky Chandler Medical Center
2. College of Public Health, University of Kentucky, Lexington, Kentucky, USA
3. London School of Hygiene and Tropical Medicine, London, UK
4. Department of Internal Medicine and Rheumatology, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
5. Department of Gastroenterology, Cleveland Clinic Florida, Weston, Florida, USA