The purpose of this trial is to demonstrate that synbioimmunonutrition (SI) combined with omega-3 fatty acids (O3) and Vitamin D (D) is superior to conventional 7-day preoperative immunonutrition in terms of reducing overall morbidity, in cases of duodenopancreatectomy for tumoral lesion.

To the best knowledge of the Investigators, a comprehensive multimodal approach to reduce postoperative morbidity in duodenopancreatectomies has not yet been evaluated. In the study, the Investigators combine the main nutritional interventions currently available and already having an individual scientific basis, sequentially and simultaneously, for a potential synergistic effect.

In cases of duodenopancreatectomy for tumoral lesion, a group of patients taking only conventional immunonutrition regimen (CIR), for 7 preoperative days, will be compared with a second group where immunonutrition will be maximised by the addition of omega 3 for 1 week prior to the administration of CIR, synbiotics for 14 days pre- and post-operatively, and preoperative vitamin D supplementation for 6 days, in terms of postoperative overall morbidity.

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