Analysis of the relationship between bile duct and duodenal microbiota reveals that dysbacteriosis is the main cause of primary common bile duct stones

Background: Bacteria play an important role in the formation of primary CBD stones. While the composition and function of the microbiota of bile duct in patients with primary CBD stones could not be explained in the whole. Intestinal dysbacteriosis is related to the formation of many diseases, but there are relatively few reports on the effects of intestinal microbial community on the formation of primary CBD stones, but none of these studies have a normal population of biliary tract and gut microbiota as control. Result: We use the 16S rRNA gene high-throughput sequencing technology to analyze the microbial diversity and community composition of biliary and duodenal microbiota in 15 patients with primary CBD stones (EG) and 4 patients without biliary tract disease (CK), and we divided above samples into four subgroups: B (EG bile), D (EG duodenal juice), BCK (CK bile)and DCK (CK duodenal juice). Alpha diversity analysis showed that only the abundance and evenness in B were lower than that in DCK (P<0.05); Beta diversity analysis showed that there were some differences in the composition between biliary microbiota and the duodenal microbiota, but the abundance of the main groups showed similarities. Proteobacteria and Firmicutes were the dominant bacteria at phylum level accounted for at least 75% of the total reads in each subgroup. It is noteworthy that Clostridium sensu_stricto (VIP>1), Lachnospiraceae _UCG-008 (VIP>1), Butyrivibrio (VIP>1) and Roseburia (VIP> 1) which could produce short chain fatty acids (SCFA), were significantly decreased in B (p<0.05) than that in BCK. Conclusion: According to the results, dysbacteriosis of biliary and duodenal microbiota plays an important role in the formation of primary CBD stones. The decrease in abundance of certain major acid-producing bacteria affects the health of the biliary tract and thus leads to the formation of stones.