Characterization of fecal microbial communities in patients with liver cirrhosis

Liver cirrhosis is the pathologic end stage of chronic liver disease. Increasing evidence suggests that gut flora is implicated in the pathogenesis of liver cirrhosis complications. The aim of this study was to characterize the fecal microbial community in patients with liver cirrhosis in comparison with healthy individuals. We recruited 36 patients with liver cirrhosis and 24 healthy controls. The fecal microbial communities was analyzed by way of 454 pyrosequencing of the 16S ribosomal RNA V3 region followed by real-time quantitative polymerase chain reaction. Community-wide changes of fecal microbiota in liver cirrhosis were observed compared with healthy controls. The proportion of phylum Bacteroidetes was significantly reduced (P=0.008), whereas Proteobacteria and Fusobacteria were highly enriched in the cirrhosis group (P=0.001 and 0.002, respectively). Enterobacteriaceae (P=0.001), Veillonellaceae (P=0.046), and Streptococcaceae (P=0.001) were prevalent in patients with cirrhosis at the family level. A positive correlation was observed between Child-Turcotte-Pugh (CTP) score and Streptococcaceae (R=0.386, P=0.02). Lachnospiraceae decreased significantly in patients with cirrhosis (P=0.004) and correlated negatively with CTP score (R=-0.49, P=0.002). Using partial least square discriminate analysis, we identified 149 operational taxonomic units (OTUs) as key phylotypes that responded to cirrhosis, most of which were Lachnospiraceae (65 OTUs), Streptococcaceae (23 OTUs), and Veillonellaceae (21 OTUs).

Fecal microbial communities are distinct in patients with cirrhosis compared with healthy individuals. The prevalence of potentially pathogenic bacteria, such as Enterobacteriaceae and Streptococcaceae, with the reduction of beneficial populations such as Lachnospiraceae in patients with cirrhosis may affect prognosis.