Bacterial community mapping of the intestinal tract in acute pancreatitis rats based on 16S rDNA gene sequence analysis

Numerous studies have revealed that the status of intestinal microbiota has a marked impact on inflammation, which may progressively aggravate the systemic inflammatory response caused by acute pancreatitis (AP). However, our understanding of microbial communities in the intestinal tract is still very limited. Therefore, the aim of this paper is deciphering bacterial community changes in AP rats. In this study, samples taken from AP rats were subjected to 16S rDNA gene sequence-based analysis to examine the characteristic bacterial communities along the rat intestinal tract, including those present in the small intestine, colon and feces, with samples from rats with a sham operation (SO) as the control group. Operational taxonomic units (OTUs) network analyses displayed that the small intestine and colon of the AP rats had a “core microbiota” composed of bacteria belonging to Firmicutes, Proteobacteria and Bacteroidetes, whereas the “core microbiota” of feces included Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes and Actinobacteria. Bacterial diversity analysis showed that the species richness and diversity of the small intestine, colon and feces in AP rats were lower than those in the SO rats, and species difference between the AP and SO groups were observed. In addition, at different levels of bacterial classification, dramatic alterations in the predominant intestinal microbiota were observed along intestinal tracts in AP rats compared to the SO rats. COG and KEGG analyses indicated that the significantly differential flora were involved several clusters and signaling networks. Thus, this work systematically characterizes bacterial communities from the intestinal tract of AP rats and provides substantial evidence supporting a prospective strategy to alter the intestinal microbiota improving AP.