Introduction The beneficial of immunonutrition on overall morbidity and mortality remains uncertain. We undertook a systematic review to evaluate the effects of immune-enhancing enteral nutrition (IEN) in upper gastrointestinal (GI) surgery.

Method Main electronic databases [MEDLINE via Pubmed, EMBASE, Scopus, Web of Knowledge, Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Library, and clinical trial registry (ClinicalTrial.gov)] were searched for studies reported clinical outcomes comparing standard enteral nutrition (SEN) and immunonutrition (IEN). The systematic review was conducted in accordance with the PRISMA guidelines and meta-analysis was analysed using fixed and random-effects models.

Results Nineteen RCTs with a total of 2016 patients (1017 IEN and 999 SEN) were included in the final pooled analysis. IEN significantly reduced post-operative wound infection (risk ratio (RR) 0.69, 95% confidence interval (CI) 0.50 to 0.94). Although, the combined results showed that IEN had a shorter hospital stay (RR –2.51 days, 95% CI –3.47 to –1.55), there was significant heterogeneity observed across these studies. There was no statistically significant benefit on other post-operative morbidities of interest (e.g. anastomotic leak and pulmonary infection) and mortality.

Conclusion IEN decreases wound infection rates and reduces length of stay. It can be recommended as routine nutritional support in upper GI surgery.

Disclosure of interest None Declared.