Impact of immunonutrition on host response Kazuhiko Fukatsu, MD Division of Traumatology, National Defense Medical College Research Institute, Saitama, Japan. Immunonutrition is a new nutritional therapy modulating host immunity and has been reported to reduce morbidity of infectious complications and hospital stay when administered to elective surgery patients. Because components of immunonutrition, immunonutrients, are nutrients contained in foods, their possible adverse effects were not frequently discussed. However, because of their strong effects on host response, some cautions have recently been given. Moreover, use of immunonutrition for severely injured and / or critically ill patients such as severe sepsis patients, is still controversial. For adequate use of immunonutrition in clinical settings, we should understand how each immunonutrient modulates host response and which timings are appropriate for their administration. In this symposium, our experimental data on impact of immunonutrition on host response will be shown in terms of gut associated lymphoid tissue (GALT), peritoneal host defense, and gut ischemia -reperfusion injury. GALT is a center of both gut and systemic mucosal immunity. Peritoneal leukocytes protect host against contamination of pathogens in peritoneal cavity. Gut ischemia reperfusion is now considered to be an important mechanism underlying severe injury-induced multiple organ failure. I would like to focus on glutamine, arginine and omega-3 fatty acids as immunonutrients.   From The 12 th PENSA Congress October 18-20 2007, Century Park Hotel. Manila, Philippines. Page: 23