Dynamic Changes of the Colonic Microbiota in Rat during Severe Acute Pancreatitis

Background: The bacterial contamination of pancreatic necrosis in acute pancreatitis is supposed to occur through translocation of intestinal bacteria. To date, the pathophysiology of the underlying bacterial translocation is poorly understood. Increased gut permeability and gut flora dysbiosis may be the initial phenomenon in this process. The present study investigated the colonic microbiota alteration pattern as well as observed colonic epithelium change in rats with SAP. Method: Denaturing gradient gel electrophoresis (DGGE) was used to monitor the colonic microbiota of control rats and experimental rats that 2, 6,and 12 hours following severe acute pancreatitis which was induced by retrograde injection of sodium taurocholate into biliopancreatic duct. Colonic samples and its contents at 1 cm distal to the cecal-colonic junction was harvested for morphological studies, streptavidin-peroxidase immunohistochemistry examination.Results: Denaturing gradient gel electrophoresis of colonic microbiota showed that gut flora pattern changed early after severe acute pancreatitis, differed significantly at 6 hours of model was induced, and then started to recover towards normal pattern. The specific dysbiosis were characterized by Escherichia coli proliferation and Lachnospiraceae and Lactobacilli reduction. As shown by immunohistochemical staining, greatly reduced expressions of ZO-1 protein were detected in rats with SAP. And the structures of junctional complexes were disrupted and the gaps between cell junctions were wider after the SAP induced.Conclusions: Severe acute pancreatitis results in colonic flora dysbiosis. And tight junction in rats with SAP was disrupted in the intestinal epithelium. Both of them may be a key factor contributing to bacterial translocations in rats with SAP.