Supplementation of an elemental enteral diet with alanyl-glutamine decreases bacterial translocation in burned mice

Abstract

Although there are many reports of the importance of early enteral feeding in maintaining gastrointestinal integrity and preventing bacterial translocation (BT) following burn injury, no diet has been shown clinically to protect the GI tract postburn. Several studies suggest that glutamine (GLN) may benefit gut integrity following injury, shock and other stress. Unfortunately, the free amino acid GLN is unstable in solution. Alanyl-glutamine (ALA-GLN), a soluble form of GLN, maintains long-term stability in solution and could be supplemented to conventional liquid enteral diets. We studied the effects of ALA-GLN supplementation of the elemental diet Vivonex TEN on effecting BT in mice following 32 per cent TBSA full skin thickness burs. Groups A–D were burned. Group A (30 mice) was fed standard rodent chow, which contains extremely high (clinically non-useable) levels of protein. Group B (51 mice) was fasted 24 h, then fed chow 24 h. Group C (64 mice) was fed Vivonex TEN, and Group D (65 mice) received Vivonex TEN plus ALA-GLN (GLN equivalent, 14g/l). A control group (Group E) consisted of 22 normal mice (no burn injury, chow diet). Mice were assessed for BT by sterile harvesting and plating of mesenteric lymph node tissue, 48 h postburn. Plates were considered positive if any bacterial growth was noted. Non-burned mice exhibited no BT, while burn-fasted mice showed a 64.3 per cent incidence of BT ( P = NS). Burned mice fed Vivonex TEN showed a 55.9 per cent rate of BT. Maximal protection against BT was afforded by rodent chow (31.0 per cent BT, P = 0.0081). We also found a reduced incidence of BT after supplementation of Vivonex TEN with ALA-GLN compared to burn-fasted animals (36.1 per cent vs 64.3 per cent BT, P = 0.009), or compared to mice fed Vivonex TEN without supplemental ALA-GLN (36.1 per cent vs 55.9 per cent BT, P = 0.046).