Efficacy and functions of Ensure enteral nutrition powder: 1.It is suitable for nutritional needs, patients whose gastrointestinal tract has digestive and absorption functions but oral intake is insufficient, simple to use and suitable for clinical application. 2.It can provide comprehensive and balanced natural nutrition, enteral nutrition can maintain gastrointestinal structure and functional integrity, protect intestinal mucosal barrier, stimulate immunoglobulin and gastrointestinal hormone secretion, and promote the recovery of intestinal function. 3.It can completely or partially replace diet, and can control or reduce the intake of low calories and nutrients.4. It can effectively help cancer patients to increase their weight and solve the problems of anorexia, loss of appetite, lack of physical strength and interruption of treatment course of tumor patients.5. It can effectively help elderly patients to improve their immune system.