[Effects of enteral nutrition and parenteral nutrition on gut epithelial tight junction and barrier function in rats after surgical stress].

OBJECTIVE: To compare the effects of enteral nutrition (EN) and parenteral nutrition (PN) on gut mucosal barrier function and intestinal epithelial tight junctions in rats after surgical stress. METHODS: Fifty SD rats with surgical trauma were randomly divided into three groups: total parenteral nutrition (TPN) group and enteral nutrition (EN) group with isocaloric and isonitrogenous nutrition and placebo group. Nutrients were administered via the neck vein and needle jejunostomy for the TPN group. The homogenated tissues of liver, lung, and mesenteric lymph nodes were cultured to determine the bacterial translocations rates. The transmembrane binding proteins (occludin) were measured with immunohistochemistry. The ultrastructure and morphology of intestinal epithelial tight junctions were observed by electron microscope. The feces in cecum were cultured for anaerobic bacterial growth analyses. RESULTS: The EN group had more lactobacteria and bifydobacteria than the TPN group, but not statistical significant. The EN group had greater expression of occludin in the intestines than the TPN group. Furthermore, the intestinal epithelial tight junction and microvilli of the EN group were more intact compared with those of the TPN group. The bacterial translocations rates of liver, lung and mesenteric lymph nodes were significantly lower in the EN group than in the TPN group. CONCLUSION: Neither EN nor standard PN maintains intestinal membrane barriers. But EN increases the expression of transmember binding proteins, maintains the gut epithelial tight junction, improves intestinal mucosal barrier and reduces gut bacterial translocation.