Past trials have shown perioperative immunonutrition to improve the outcome for patients with gastric cancer. The present study was designed to evaluate the effect of preoperative oral immunonutrition on cellular immunity, the duration of the systemic inflammatory response syndrome (SIRS), and detailed postoperative complications in patients with gastric cancer.

Sixty patients with gastric cancer were randomly assigned to two groups: one group received immune-enhanced formulas supplemented with arginine and omega-3 fatty acids (immune-enhancing diet (ID) group, n = 30); the other received standard formulas (conventional diet (CD) group, n = 30) for 7 days before the operation. These groups were well matched in terms of age, sex, operations, cancer stages, and intraoperative variables. The postoperative outcome was evaluated based on clinical variables, including postoperative infectious complications, noninfectious complications, and SIRS duration. In addition, the perioperative state of cellular immunity was evaluated and compared between the two groups.

The incidence of postoperative infectious complications in the ID group (6%) was significantly (p < 0.05) lower than that of the CD group (28%). The duration of SIRS in the ID group (0.77 +/- 0.9 days) was significantly (p < 0.05) shorter than that in the CD group (1.34 +/- 1.45 days). The postoperative lymphocyte and CD4(+)T-cell counts significantly decreased (p < 0.05) in both groups. However, the number of CD4(+)T-cells on preoperative day 1 and postoperative day 7 was significantly (p < 0.05) higher in the ID group than in the CD group.

Preoperative oral immune-enhanced formulas supplemented with arginine and omega-3 fatty acids enhanced the immune status of the patients, reduced the duration of SIRS, and decreased the incidence of postoperative infectious complications. CD4(+)T-cell immunity likely played an important role in the modulation of the postoperative immune and inflammatory response after gastrectomy.