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 our study is 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 people as control. The fecal microbial community was analyzed by 454 pyrosequencing of the 16S ribosomal RNA (16S rRNA) V3 region followed by real-time quantitative PCR (qPCR). Community-wide changes of fecal microbiota in liver cirrhosis were observed compared with healthy controls (Figure 1). The proportion of phylum Bacteroidetes was significantly reduced (p=0.008), while 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 cirrhotic patients at the family level. A positive correlation was observed between Child-Turcotte-Pugh (CTP) score and Streptococcaceae (R=0.386, p=0.02). Lachnospiraceae significantly decreased in the cirrhotics (p=0.004), and correlated negatively with CTP score (R=-0.49, p=0.002). By Partial Least Square Discriminate Analysis (PLS-DA), we identified 149 operational taxonomic units (OTUs) as key phylotypes that responded to cirrhosis, and most of them were Lachnospiraceae (65OTUs), Streptococcaceae (23 OTUs), and Veillonellaceae (21 OTUs) (Figure 2). Fecal microbial communities are distinct in cirrhotic patients 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 cirrhotics may affect prognosis. This paper was published in Hepatology.