Impairment of lymphocyte function in head-injured rats: Effects of standard and immune-enhancing diets for enteral nutrition

Background The metabolic response to head injury (HI) is characterized by a dysimmunity which may be a risk factor of a septic state. The use of immune enhancing diets (IEDs) could be a promising approach to improve immune functions. The aim of the study was to investigate the consequences of HI on lymphocyte function and to determine the effects of an enteral IED comparatively to a standard enteral nutrition. Method A rat model of HI by fluid percussion was used. Twenty-five male Sprague–Dawley rats were randomized into 4 groups: rats receiving standard chow diet ad libitum (AL), rats sustaining HI and receiving standard chow diet and enteral saline (HI), rats receiving the enteral standard diet Sondalis HP® (HIS), and rats receiving the IED Crucial® (HIC). The two enteral diets were infused continuously during 4 days after the HI and were isocaloric, isonitrogenous and isovolumic. Results HI induced a thymus atrophy (HI vs. AL, P<0.05), and an impairment in lymphocyte CD25 receptor density responsiveness to stimulation. The IED blunted thymus atrophy and allowed to preserve the stimulation of blood and Peyer patches lymphocytes (HIC: Stimulated vs. Basal, P<0.05). Conclusion IED seems more adapted for preserving lymphocyte function than standard diet in HI patients.