1. Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow 226014, India
2. Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow 226014, India
3. Stomach, Liver and Bowel Clinic, Gleneagles Hospital, Singapore
4. Department of Medicine and Therapeutics, Institute of Digestive Disease, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong
5. Department of Medicine, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland