Oral Immunonutrition With Synbiotics, Omega 3 and Vitamin D in Patients Undergoing Duodenopancreatectomy for Tumoral Lesion.

Inclusion Criteria: * All cases of duodenopancreatectomy for tumoral lesions. Exclusion Criteria: * Distal or total pancreatectomies, as well as procedures for chronic pancreatitis * Patient refusal or inability to provide informed consent * Use of dietary supplements containing omega 3, pre- or probiotics within 15 days prior to protocol initiation * Severe cardiorespiratory or renal insufficiency * HIV * Cirrhosis Child-Pugh B-C * Inability to feed by mouth * Intestinal obstruction * Unresectable tumor or metastatic disease on preoperative work-up * Cardiac valvular pathology * Short bowell syndrome * Haemophilia * Known allergy or intolerance to fish oil, fish or shellfish, milk, soy or components of the products used * BMI \< 16kg/m2 * Weight loss \> 15% in the last 6 months * Little or no food in the last 10 days * Hypercalcemia * Pregnancy, breastfeeding