1. Gastroenterology and hepatology Unit, Department of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur , Malaysia
2. GUT Research Group, Faculty of Medicine, Universiti Kebangsaan Malaysia , Kuala Lumpur , Malaysia
3. Department of Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
4. Department of Gastroenterology and Hepatology, Selayang Hospital , Kuala Lumpur , Malaysia
5. Department of Pharmacology, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur , Malaysia
6. Gastroenterology and Hepatology Unit, Serdang Hospital , Selangor , Malaysia