ObjectiveTo evaluate the effect of the early enteral nutrition(EEN) on the natural course in dogs with severe acute pancreatitis(SAP).MethodsSAP model was induced by injecting 1 ml/kg of combined solution of 5% sodium taurocholate and 8 000-10 000 BAEE units trypsin/ml into pancrease via pancreatic duct.Fifteen dogs were divided into parenteral nutrition(PN) group and EEN group.Two groups were isonitrogenous and isocaloric.EEN was used at postoperative 24 h.Systemic plasma endotoxin level was quantified by the chromogenic limulus amebocyte lysate technique.Both portal and systemic blood sample were obtained before and 1,4,7 d following SAP, and cultured for aerobic as well as anaerobic bacterial.Serum glucose, calcium,amylase and lysosomal enzymes were determined.All dogs were injected with 1.85×106 Bq 125IBSA 4 h before sacrificed.The 125IBSA index of the pancreas/muscle and pancreas/blood was measured,and pancreas pathology was observed.Specimens of tissue from mesenteriolum and mesocolon lymph nodes,lung,pulmonary portal lymph nodes and pancreas were removed,weighed and homogenized in grinding tubes.Aliquots of the homogenata were cultured as blood mentioned above.The thickness of mucosa,the whole gut layer,the height of intestinal villi and their protein and DNA contents in the intestinal and transverse colon were determined.ResultsThe study showed that EEN significantly reduced the levels of systemic plasma endotoxin and the magnitude of bacterial translocation to the portal and systemic blood and distant organ,serum glucose in PN group was higher than that in EEN after SAP 4 d.There were no difference between two groups in the data of serum calcium,amylase and lysosomal enzymes,pathologic index and 125IBSA index of pancreas/muscle and pancreas/blood.EEN improved the gut barrier function by increasing the thickness of mucosa,the whole gut layer and the height of intestinal villi,increasing its protein and DNA contents in the bowel.ConclusionOur results suggest that EEN is safe and effective,and can decrease the rate of intestinal bacterial translocation.