Ernst was also a member of the Governing Board of the National University Health System in Singapore, and a member of the Board of Curaçao Medical Center. He further acted as chair of the Dutch National Emergency Medicine Network, which played a major role during the Covid pandemic. Ernst chaired the board of the Netherlands Federation of University Medical Centres and was a member of the Dutch National Health Council.

Ernst earned a medical degree from University of Groningen, completed training in Internal Medicine and Gastroenterology and wrote a thesis on Helicobacter pylori and gastric cancer. He subsequently worked at Vanderbilt University Medical Center in Nashville, Tennessee, in the USA, and then joined Erasmus MC. His clinical and research interests include early neoplastic gastrointestinal conditions, with a focus, among other things, on cancer screening. Under his supervision, many students completed their theses. He is a fellow of the American Gastroenterological Association, Honorary Member of the European Helicobacter & Microbiota Study Group, and an Honorary Fellow of the Hong Kong Society of Gastroenterology. He served as the World Endoscopy Organization’s regional lead on colorectal cancer screening for Europe and the Middle East. He co-organized and contributed to various international guidelines on gastrointestinal neoplasia.

Ernst is the recipient of many awards, including the Dutch Ministry of Health Pearl Award, the Influencer of the Year Award in Hospital Healthcare, the Ismar Boas Medal of the German Gastroenterology Society, the United European Gastroenterology Research Prize, the Innovation Award of the German Felix Burda Society, a Clinical Mentorship Award by the American Gastroenterology Association, and the Dutch Healthcare Executive of the Year Award.