Diversity And Assciation Of Oral And Fecal Microbiota In Patients With Ascites Cirrhosis

Objectives: 16 S rRNA gene sequencing was used to observe the different aspects of oral and intestinal microflora among healthy population,cirrhosis patients with ascites or not and patients with different ascites grades,so as to make a thorough inquiry of the relationship between oral and intestinal microflora in cirrhotic patients with ascites.Methods: Selecting 19 patients with cirrhosis without ascites(CWA)served as the control group and 33 patients with cirrhosis with ascites(CA)as the trial group from June2020 to November 2020 from the Hebei University of Engineering Affiliated Hospital and the Infectious Disease Hospital of Handan.In addition,19 healthy volunteers in the same period were collected as the healthy group(HC).According to the Guidelines for the Diagnosis and Treatment of Cirrhosis Ascites and Related Complications,the CA group was divided into three groups: grade 1(CAA),grade 2(CAB)and grade 3(CAC).the grade B(CAB)and the grade C(CAC)according to the results of B-ultrasound.The saliva and feces of the subjects were collected respectively.The DNA of samples were extracted and detected,and 16 S rRNA V3-V4 region gene sequencing was used to compare the high-quality data information with greenene database,to preliminarily explore the relationship between oral and intestinal microflora in patients with cirrhosis ascites,and to study the abundance and diversity of oral and intestinal microflora in patients with cirrhosis with ascites progression.Results:(1)OTU clustering of oral and intestinal microflora in HC,CWA and CA groups showed 58 identical OTU of oral and intestinal microflora.(2)The histogram and Graphlan graph of relative abundance of species composition in HC,CWA and CA groups showed that the main species of oral and intestinal microbiota were Firmicutes,Bacteroidetes,Proteobacteria at the phylum level.At the genus level,although there were significant differences in the composition of oral and intestinal microflora,some genus were common to oral and intestinal microflora.Rothia,Granulicatella and Campylobacter were concentrated in the oral cavity,almost not detected in the feces of the HC group,but could be detected increasingly in the feces of the CWA and CA groups.(3)The OTU annotation results of the HC,CWA and CA groups showed that the abundance of Proteobacteria in intestinal microbiota decreased at the phylum level,and the abundance in the CA group was dramatically lower than that in the HC group(P < 0.05).At the genus level,the abundance of Megamonas and Lachnospira showed a downward trend,and the abundance of Megamonas in the CA Group was dramatically lower than that in the HC group(P < 0.05),the abundance of Lachnospira in the CWA and CA groups were dramatically lower than that in the HC group(P < 0.05),while the abundance of Escherichia showed an upward trend,and the abundance of Escherichia in CA Group was dramatically higher than that in the HC group(P < 0.05).At the phylum level,the abundance of Firmicutes increased,and the abundance of Firmicutes in the CWA and CA groups was dramatically higher than that in the HC group(P < 0.05),while the abundance of Proteobacteria decreased,and the abundance of Proteobacteria in the CA Group was dramatically lower than that in the HC group(P < 0.05).At the genus level,the abundance of Capnocytophaga and Veillonella increased,and the abundance in the CA Group was dramatically higher than the HC group(P < 0.05),while the abundance of Haemophilus decreased,and the abundance in the CWA and CA groups were dramatically lower than the HC group(P < 0.05).(4)The results of species composition of the CWA group and the CA subgroups showed that Prevotella showed a downward trend at the genus level,and the abundance in the CAFe A,CAFe B and CAFe C groups were dramatically lower than the CWAFe group(P < 0.05),while the abundance of Clostridium showed an upward trend,and the abundance in the CAFe B and CAFe C groups were dramatically higher than that in the CWAFe group(P < 0.05).At the genus level,with the ascites grading increased the abundance of Veillonella increased while that of Haemophilus decreased(P > 0.05),and there was no statistical significance in the comparison between groups.(5)The LEFSe results of the HC,CWA and CA groups showed the bacteria which played a significant role in the intestinal flora of the HC group were Rikenellaceae,Turicibacteraceae and Clostridium,while the bacteria that played a significant role in the CA group were Micrococcaceae and Rothia.In oral bacteria,Pasteurellaceae and Gammaproteobacteria played a considerable role in the HC group,Aggregatibacter played a considerable role in the CWA group,and Actinomycete,Coriobacteria,Flavobacteria,Lactobacillus,Leptotrichiaceae and Desulfovibrio desulfurizer played a considerable role in the CA group.(6)The results of Alpha diversity analysis showed that the diversity and richness index of oral and intestinal microflora the CA group decreased dramatically compared with the HC and CWA groups,and further decreased with the increase of ascites grade.(7)The results of Beta diversity in the HC,CWA and CA groups showed that there were obvious contrasts in oral and intestinal microflora in the unweighted PCOA map,and the differences among individuals of intestinal microflora were more tremendous than those among individuals of oral bacteria.There were obvious contrasts in oral and intestinal microflora between the CWA group and each CA subgroup in PLS-DA diagram.Conclusions:(1)There were great differences in oral and intestinal microflora composition in cirrhotic patients with ascites,but there were common species.Compared with the healthy group and the cirrhotic group without ascites,the shift of oral flora to intestinal flora increased in the cirrhotic ascites group.(2)The number of opportunistic bacteria in the oral and intestinal microflora of cirrhotic patients with ascites was dramatically increased,while the number of beneficial bacteria was dramatically decreased.(3)With the development of cirrhosis ascites,there were obvious contrasts in oral and intestinal microflora of some species at phylum and genus levels.