A prospective, randomized clinical trial on perioperative feeding with an arginine-, omega-3 fatty acid-, and RNA-enriched enteral diet: Effect on host response and nutritional status

Background: The use of immune-enhancing enteral diets in the postoperative period has given contrasting results. The purpose of this prospective, randomized, double-blinded clinical study was to evaluate the effect of immunonutrition given perioperatively on cytokine release and nutritional parameters. Methods: Patients with cancer of the stomach or colo-rectum were eligible. Subjects consumed 1 L/d of either a control enteral formula (n = 25; control group) or a formula supplemented with arginine, omega-3 fatty acids, and RNA (n = 25; verum group) for 1 week before surgery. Both formulas were given by mouth. Six hours after the operation, jejunal infusion with the same diets was started and maintained for 7 days. Blood was drawn at different time points to assess albumin, prealbumin (PA), transferrin, cholinesterase activity, retinol binding protein (RBP), interleukin-2 receptors alpha (IL-2R alpha), IL-6, and IL-1 soluble receptors (IL-1RII). The composite score of delayed hypersensitivity response (DHR) to skin test also was determined (the higher the score, the lower the immune response). Results: During the 7 days of presurgical feeding, none of the above parameters changed in either group. Eight days after operation, in the control group, the concentration of PA and REP was lower than in the verum group (0.18 vs 0.26 g/L for PA and 30.5 vs 38.7 mg/L for REP; p < .05). IL-2R alpha concentration was 507 pg/mL in the verum group vs 238 pg/mL in the control group (p < .001), whereas IL-6 and IL-1RII were higher in the control group than in the verum group (104 vs 49 and 328 vs 183 pg/mL, respectively; p < .01). The DHR score was 0.68 in the control group vs 0.42 in the verum group (p < .05). Conclusions: Perioperative feeding with a supplemented enteral diet modulates cytokine production and enhances cell-mediated immunity and the synthesis of short half-life proteins.