Effect of Periampullary Diverticulum on Biliary Flora and the Formation of Common Bile Duct Stone

Abstract

Background: Bile duct stone is closely related to periampullary diverticulum, but it is not clear whether the formation of it was affected by the diverticulum through the biliary flora. To explore the diversity and correlation of biliary and intestinal flora in the patients with choledocholithiasis and the effects of periampullary diverticulum on the flora and bile duct stone. Methods: Bile and intestinal fluid were collected from patients with primary common bile duct stones, and then divided into diverticulum group and none- diverticulum group according to the presence or absence of paravertebral diverticula, DNA of these samples was extracted and a bacterial gene library was constructed, and related bioinformatics analysis was performed after high-throughput sequencing to obtain the bacterial components and community structure of the sample. Result: A total of 3001,613 valid sequences were obtained, with an average of 136436.95±3696.842 sequences, which were classified into 6021 ASV/OUT. Alpha diversity analysis showed that the species richness and diversity in the diverticulum group were lower than those in the nondiverticulum group. According to the species annotation results, the advantage bacterium group of the bile is Proteobacteria (BG 80.41%, Bg 70.95%), and advantage bacterium group of the intestinal fluid is Firmicutes and Proteobacteria (BG 89.39%, Bg 74.11%). A large proportion of Enterobacter was found in bile. Escherichia coli, Klebsiella, Streptococcus and other bacteria closely related to stone formation have been found. The proportion of E. coli in the diverticulum group was increased and due to the existence of the diverticulum Enterobacteria in the bile were increased and more complex. The bacteria that produce Betaglucuronidase are found to be increased in bile. Due to the influence of the periampullary diverticulum, the intestinal flora will be changed and then the biliary flora will also change. Conclusion: The existence of periampullary diverticulum will affect the biliary tract flora and lead to the increase of bacteria related to stone formation, which will affect the formation of choledocholithiasis and make it easier for choledocholithiasis to form.