Effects of long-term continuous use of immune-enhancing enteral formula on nutritional and immunologic status in non-surgical patients

ObjectiveAlthough the perioperative use of immune-enhancing enteral formula (IEEF) effectively reduces the rate of infectious complications, whether chronic use of IEEF is beneficial is unknown. A prospective randomized clinical trial was performed to examine the safety and effectiveness of long-term IEEF on nutritional and immunologic status in non-surgical patients receiving total enteral nutrition through the gastrostomy access route.MethodsA total of 30 patients were randomly assigned to two groups in which they received total enteral nutrition, an IEEF (n = 15) or a regular polymeric enteral formula (control group; n = 15) for 12 wk. Nutritional and immunologic variables were periodically examined.ResultsSerum concentrations of insulin-like growth factor-I increased significantly for the IEEF group throughout the study. Although serum concentrations of dihomo-γ-linoleic acid decreased significantly in the IEEF group, serum concentrations of eicosapentaenoic acid and docosahexaenoic acid increased significantly, as did concentrations of serum arginine and ornithine. The CD4/CD8 ratio and natural killer cell activity also increased for the IEEF group, but the differences were not significant. The B-cell fraction increased and the T-cell fraction of peripheral lymphocytes decreased for the IEEF group. Neither infectious nor non-infectious complications occurred during the study period in either group, except for a significant increase in serum urea nitrogen and uric acid concentrations for the IEEF group.ConclusionLong-term use of IEEF is safe in non-surgical patients and results in a significant increase in serum insulin-like growth factor-I concentrations in association with increased humoral immunity.