Editorial: Diet and the Gut 1. Health Policy Research Center, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran

29th of May has been convened as the World Digestive Health Day (WDHD) by the World Gastroenterology Organization (WGO) since 2005. This event is an opportunity to raise public awareness on topics related to gastrointestinal tract diseases and health. The theme of 2016 is “diet and the gut”. The traditional approach to diet in gastroenterology practice is to advise patients to avoid certain foods to control their symptoms and /or diseases. The classic example of causative role of food in a disease is celiac disease for which the main management is gluten free diet (GFD).1 In patients with lactase or fructase deficiency, ingestion of lactose or fructose would lead to flatulence. Many such patients have learned to avoid certain foods. Food allergy is yet another example of food as a cause of disease. Examples include milk and wheat allergy. The latter should not be confused with celiac disease because of different pathogenesis and clinical presentations.2