TOTAL PARENTERAL-NUTRITION, BACTERIAL TRANSLOCATION, AND HOST IMMUNE FUNCTION

Total parenteral nutrition (TPN) is associated with increased infectio us complications in trauma and perioperative patients compared with en teral nutrition support. This study evaluated the effects of TPN on sp lenocyte and peritoneal macrophage (PM(D) function and intestinal bact erial translocation. Male Wistar rats underwent central vein cannulati on and were randomized to isocaloric feeding of a regular chow diet (R D) plus saline infusion or TPN for 7 days. Splenocytes and PM0 were ha rvested to assess concanavalin A mitogenesis, superoxide production, a nd Candida albicans phagocytosis. Bacteria-positive mesenteric lymph n odes (MLNs) were found in 77% (10 of 13) of TPN-fed rats compared with 17% (2 of 12) of RD-fed rats (p<0.05). Splenocyte mitogenesis, PM0 su peroxide production, and C. albicans phagocytosis were significantly d ecreased in the TPN group compared with results in the RD group. In a second study, rats received RD, TPN, and parenteral nutrition (PN) wit h 10% or 20% of calories given as oral chow (PN and 10% chow and PIV a nd 20% chow) for 7 days. PN and 10% chow reversed the TPN-induced supp ression of C. albicans phagocytosis. PN + 20% chow significantly incre ased splenocyte mitogenesis, PM0 superoxide production, and C. albican s phagocytosis and killing to normal levels and was associated with a decreased incidence of bacteria-positive MLN. Thus, administration of TPN is associated with impaired PM0 microbicidal and splenocyte prolif erative function. These defective cellular functions were reversed wit h a small amount of oral feeding.