Study Of Biliary Microbial Community Of Patients With Common Bile Duct Stones And The Relationship Between Biliary Microflora And Recurrent Common Bile Duct Stones

Objective: This study aimed to explore the structure composition and diversity of biliary microbial community in patients with common bile duct stones(CBDS)and the relationship between the biliary microflora and the recurrence of CBDS.Methods: In this study,23 patients who underwent ERCP surgery at the First Hospital of Lanzhou University due to CBDS were recruited from September 2018 to November 2018,including the 14 patients with primary CBDS and 9 patients with recurrent CBDS.The basic clinical data,medical history and preoperative test results of all patients were collected,and the patient's common bile duct bile samples were collected during ERCP.The microbial DNA of all samples was extracted and expanded by PCR,and 16 S rDNA high-throughput sequencing technology was used for sequencing analysis to identify bacterial OTU.According to the results of species classification and annotation,the structure,composition and diversity of biliary microflora in patients with CBDS were described,and the differences of biliary microflora in patients with recurrent CBDS and those with primary CBDS were compared and analyzed.Results: The detection rate of bacterial DNA in the common bile duct bile in patients with CBDS was 100%.A total of 579599 high-quality tags were obtained,with an average of 25200±11429 tags per sample,of which 325559 tags were obtained from primary CBDS and 254040 tags were obtained from recurrent CBDS.A total of 1075 bacterial OTUs were identified,with an average of 191±66 OTUs per sample,of which 830 OTUs were obtained from primary CBDS and 824 OTUs were obtained from recurrent CBDS.According to the classification results of the species classification,all OTUs belong to 17 bacterial phylum and 221 bacterial genera,among which there were 17 phylum and 194 genera of primary CBDS,and 13 phylum and 165 genera of recurrent CBDS.The dominant flora in the biliary tract of patients with primary CBDS and those with recurrent CBDS are Proteobacteria and Firmicutes,among which Escherichia was the most abundant.Compared with patients with primary CBDS,the structure and composition of biliary flora was more similar in patients with recurrent CBDS,and species diversity was lower.At the phylum level,the mean abundance of firmicutes in the biliary flora of patients with recurrent CBDS was increased,while the mean abundance of other phylum was decreased.At the genus level,the average abundance of Escherichia,Enterococcus and Klebsiella in patients with recurrent CBDS were 2.5 times,2.7 times and 82 times higher than that in patients with primary CBDS,respectively,while the average abundance of most other genera decreased.Conclusion: In this study,Illumina MiSeq sequencing platform was used for 16 S rDNA high-throughput sequencing analysis of the biliary microflora in patients with CBDS,so as to describe the structure and composition of the biliary flora in patients with CBDS.The detection rate of bacteria in the biliary tract of patients with CBDS is 100%.The differences of biliary flora between patients with recurrent CBDS and those with primary CBDS were compared and analyzed.The species diversity of biliary flora in patients with recurrent CBDS was lower.This study indicates that the imbalance of biliary bacterial community may be related to the recurrence of CBDS.