Detection Of SIBO In Patients With Cholangiocarcinoma And Preliminary Study On High-throughput Sequencing Of Bacteria In Cholangiocarcinoma Tissues And Paracancerous Tissues

Objective:To explore the situation of small intestinal bacterial overgrowth?SIBO?in patients with cholangiocarcinoma.To investigate the existence of bacteria in the cholangio-carcinoma tissues according to the Illumina HiSeq sequencing platform.To compare the results with the intestinal flora if any bacteria were present in cholangiocarcinoma tissues.And to take further analysis about the general distribution,abundance,and diversity of the species of the flora and compare it with the adjacent normal tissues at the same time.Methods:34 cases of cholangiocarcinoma who knew the details,agreed and signed the consent,were selected of Qingdao Municipal Hospital affiliated to Qingdao University from December 2016 to February 2018.At the same time,30 healthy volunteers were randomly selected as a control group for the detection of small intestinal bacterial overgrowth.Glucose hydrogen breath test?GHBT?was used to detect small intestinal bacterial overgrowth in 34 patients with cholangiocarcinoma and 30 healthy controls.The samples from the tumor and adjacent normal tissues in patients with cholangiocarcinoma were collected intraoperatively.High-throughput sequencing of 16S rDNA V3+V4 was performed on the cholangiocarcinoma tissues and paracancerous tissues,which near the lumen side,using the Illumina HiSeq sequencing platform,and sequencing results were obtained.The sequencing results were analyzed in terms of distribution,abundance and diversity of the flora.Statistical software was adopted for analysis.Results:1.The positive rate of SIBO in patients with cholangiocarcinoma?55.88%?was significantly higher than that in healthy controls?16.67%?,and the difference was statistically significant?c²=10.458,P<0.05?.2.High-throughput sequencing results showed that bacteria existed in both cholangio-carcinoma and paracancerous tissues,and the bacterial species were consistent with the intestinal flora,but the composition ratios were different.The results of abundance and diversity analysis of bacterial flora showed that there was no significant difference in the abundance and diversity of bacterial populations between the cholangiocarcinoma tissues and the paracancerous tissues.There was no significant difference in Chao1,Ace,Shannon and Simpson between the two groups?P>0.05?.3.At the level of Phylum:The dominant phyla of both specimens were Firmicutes,Bacteroidetes and Proteobacteria.The proportion of dominant phyla in specimens of cholangiocarcinoma and paracancerous tissues were 31.6%,25.1%,17.7%and 48.2%,36%,6%.4.At the level of Genus:The relative abundance of the genus was sorted in the group of cholangiocarcinoma tissues:Helicobacter 11.0%,uncultured_bacterium_fBacteroi-dales_S24_7group 7.1%,Lachnospiraceae_Nk4A136_group 4.1%,uncultured_Bacterium_fLachnospiraceae 3.2%,Bacteroides 2.8%,Alistips 2.6%,Prevotella-9 2.1%,Desulfo-microbium 0.9%.And the relative abundance of the genus was sorted in the group of paracancerous tissues:uncultured_bacterium_fBacteroidales_S24_7group 11.1%,Bac-teroides 6.4%,Alistips 5.9%,Lachnospiraceae_Nk4A136_group 4.9%,Desulfomicrobium4.0%,Prevotella-9 3.2%,Helicobacter 1.9%.Conclusion:1.Compared with healthy people,patients with cholangiocarcinoma are more likely to have SIBO.2.Bacteria was found in both cholangiocarcinoma tissues and paracancerous tissues according to the high-throughput sequencing.The bacterial flora may mainly originate from the intestinal microbiota.Although the species was generally the same,the composition ratio was different from the gut microbiota.On the level of phylum,compared with the paracancerous tissue,the proportion of Firmicutes and Bacteroidetes decreased,while the proportion of Proteobacteria increased.At the genus level,the proportion of Helicobacter in the cholangiocarcinoma tissue was higher than that in the paracancerous tissue,and the proportion of Bacteroides,Alistips,Prevotella-9,uncultured_bacterium_fBacteroidales_S24_7group,Desulfomicrobium was lower than those in the paracancerous tissue.There was no significant difference in the overall abundance and diversity between the two groups.3.The intestinal flora may participate in the occurrence and development of cholangiocarcinoma.It is very important to carry out further study on the intestinal flora for the diagnosis and treatment of cholangiocarcinoma.