Understanding The Structural Shifts Of Gut Microbiota In Patients With Chronic Viral Hepatitis B

Chronic infection of Hepatitis B virus (CHB) still is a global infectious disease with serious sequelae. Recent evidence suggests that among many factors that contribute to the pathogenesis of hepatitis, gut microbiota plays an important role in exacerbation of inflammation and fibrosis in the liver. The aim of this study was to assess the differences between the composition of the gut microbiota in humans with CHB and Health individuals as control.Fresh faecal samples from 300 CHB patients and 149 healthy control individuals were collected. 851,302 sequences of microbial V3 region of the 16S rRNA genes were examined by using bar-coded 454 pyrosequencing technology and clusted into 3754 operational taxonomic units (OTUs) with a similarity cutoff at 97%. The pyrosequencing data were analyzed with multivariate statistical methods and the result showed that significant structural changes occurred in the gut microbiota with CHB. Overall, the gut microbiota of CHB patients was associated with a decrease in the level of diversity compared with the healthy individuals. The abundance of Bacteroidetes was significantly increased, whereas Firmicutes was reduced in the CHB group compared to the Health (P < 0.01). Furthermore, in the genus level, the abundance of Prevotella was remarkably enriched and gut barrier-protecting bacteria Bifidobacterium as well as Roseburia were reduced in CHB (P < 0.01).In conclusion, the results of this study indicate that significant structural shifts of gut microbiota were occurred in the CHB patients. These shifts were caused by reduced bacterial diversity and alteration of some key populations including Prevotella, Roseburia, Bifidobacterium, etc.