['To determine whether early enteral feeding in a septic intensive care unit (ICU) population, using a formula supplemented with arginine, mRNA, and omega-3 fatty acids from fish oil (Impact), improves clinical outcomes, when compared with a common use, high protein enteral feed without these nutrients.', 'A prospective, randomized, multicentered trial.', 'ICUs of six hospitals in Spain.', 'One hundred eighty-one septic patients (122 males, 59 females) presenting for enteral nutrition in an ICU.', 'Septic ICU patients with Acute Physiology and Chronic Health Evaluation (APACHE) II scores of > or =10 received either an enteral feed enriched with arginine, mRNA, and omega-3 fatty acids from fish oil (Impact), or a common use, high protein control feed (Precitene Hiperproteico).', 'One hundred seventy-six (89 Impact patients, 87 control subjects) were eligible for intention-to-treat analysis. The mortality rate was reduced for the treatment group compared with the control group (17 of 89 vs. 28 of 87; p < .05). Bacteremias were reduced in the treatment group (7 of 89 vs. 19 of 87; p = .01) as well as the number of patients with more than one nosocomial infection (5 of 89 vs. 17 of 87; p = .01). The benefit in mortality rate for the treatment group was more pronounced for patients with APACHE II scores between 10 and 15 (1 of 26 vs. 8 of 29; p = .02).'] Does an immune-enhancing enteral diet reduce mortality rate and episodes of bacteremia in septic intensive care unit patients?