John Leung, MD attended medical school at University of Michigan Medical School and completed his internal medicine residency at University of Iowa Hospitals and Clinics. He then finished a Gastroenterology fellowship at Tufts Medical Center. He worked as a gastroenterology consultant at Tufts Medical Center for a year before completing an Allergy/Immunology clinical and research fellowship at Massachusetts General Hospital/Harvard Medical School.

He is the only US physician dual board certified in Allergy/Immunology and Gastroenterology. He is the CEO and founder of Boston Specialists LCC. He is a site principal investigator of Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGiR), and has been continuously funded by the National Institutes of Health since 2014. He has conducted over 30 industry and federal funded clinical trials since 2010. He is the director of Center for Food Related Diseases at Tufts Medical Center and director of Director of Food Allergy Center at Tufts Children’s Hospital.

His clinical and research focus are on eosinophilic gastrointestinal diseases and food allergy. He has coauthored more than 50 peer-reviewed manuscripts, numerous scientific abstracts, book chapters, and online tutorials.