Abstract: Objective To explore the characteristic of intestinal flora changes in patients with chronic hepatitis B （CHB）,liver cirrhosis （LC） and liver failure （LF）. Methods 23 patients with CHB,20 with LC,6 with LF and 9 healthy persons were recruited in this study. The morning excrements in the 58 cases were collected to test the intestinal flora,and the fecal intestinal flora DNA was obtained by fecal bacterial genome DNA extraction kits. The 16SrDNA of metagenomics sequencing technology was applied to analyze the intestinal flora. The biology and SPSS statistical software were applied to analyze the sequencing results to compare the differences of the intestinal flora in patients with CHB,LC and LF. Results In the phylum level of intestinal flora,all samples showed priority to Bacteroidetes,and secondly was Proteobacteria. Bacteroidetesa bundance in patients with CHB （617.83） was much greater than in with LC （343.16） or with LF （182.15） or in healthy persons （236.66,P<0.05）;Proteobacteria in patients with LC（183.16） was much greater than in with CHB （35.86）,with LF（18.87） or in healthy group（53.40,P<0.05）;in the genus,all samples showed the priority to Bacteroides,and secondly were Prevotella and Fusobacterium. Prevotellaa bundance in patients with CHB （345.28） was much greater than in with LC（46.75）,in with LF（5.63） or in healthy group（20.14）;Bacteroides was the least flora in patients with LC（150.28,P<0.05）. Conclusions Bacteroidetes is the dominant bacteria in all samples and the main difference of flora is the abundance in patients with HBV infection. The Proteobacteria is the most flora in patients with CHB,but is the least in patients with LC and Veillonella increases in patients with LF.

Key words: Liver cirrhosis, Hepatitis B, Liver failure, Intestinal flora