Gut Flora in Intestinal and Extraintestinal Diseases: A General Overview and the Effects of Artificial Nutrition

The intestine harbors a complex and dynamic microbial ecosystem which plays a primary role in human physiology. Major functions of the gut flora include metabolic activities, gut trophic and protective effects and interactions between the immune system and the host. In some pathological disorders (pancreatic and liver disease, H.pylori infection, inflammatory bowel diseases, etc.), gut flora may also play an essential causal role. Finally, Artificial Nutrition induces dramatic changes in the intestinal flora which may contribute to the possible complications linked to this type of treatment. This review provides an update on the role of gut flora in some pathological conditions, and its changes during Enteral and Parenteral Nutrition.