Comparison of the Gut Microbe Profiles and Numbers Between Patients with Liver Cirrhosis and Healthy Individuals Jianjun Liu • Dachang Wu • Ayaz Ahmed • Xinli Li • Yufang Ma • Li Tang • Dianjun Mo • Yue Ma • Yi Xin Received: 6 November 2011 / Accepted: 24 February 2012 / Published online: 7 April 2012 Ó Springer Science+Business Media, LLC 2012 Abstract Human liver was closely associated with gut through various biological mechanisms, such as bacte- rium–gut interactions. Alterations of gut microbiota seemed to play an important role in induction and pro- motion of liver damage progression. The aim of this study was to characterize the gut microbiota in liver cirrhosis patients and assess whether there are alterations in the diversity and similarity of intestinal flora in cirrhotic patients when compared with healthy individuals. PCR- denaturing gradient gel electrophoresis (DGGE) with uni- versal primers targeting V3 region of the 16S rRNA gene was employed to characterize the overall intestinal mic- robiota composition, and some excised gel bands were cloned for sequencing. Real-time PCR was further utilized to quantitatively analyze the subpopulation of microbiota using group-specific primers targeting the Enterobacteria- ceae, Enterococcus and Bifidobacterium genus. The DGGE profiles of two groups demonstrated significant differences between cirrhotic and healthy groups (P \ 0.05). While real-time PCR revealed significant increase of Enterobac- teriaceae and Enterococcus (P \ 0.05) in the cirrhotic group compared with the healthy group. The ratio of Bifi- dobacterium genus and Enterobacteriaceae decreased in the cirrhotic patients group, but no statistical significance. This study revealed strong relationship between alterations of gut microbiota and liver cirrhosis. Introduction By the virtue of advances in the meta-genomics field we came to know that microorganisms associated with the human body are ten times more than the cells in the human body, containing aggregates of about 100 times more genes and considered as a ‘‘microbial organ’’ [3, 15]. Some caused disease but most of them played a vital role in human physiological processes. The intestinal microbiota is one of the complex ecological systems in body that perform critical functions for body like production of vitamins, degradation of bile acids and non-digestible polysaccharides, local and general immunity, the devel- opment of the intestinal microvillus, and participance in forming an important barrier against pathogen together with the intestinal mucosa [1, 5, 30]. Human liver is strongly related to the gut in terms of biological function and pathogenic process. The portal sys- tem receives blood from the gut, and intestinal blood content activates liver functions. The liver, in turn, influences intestinal functions through bile secretion [29]. Liver cir- rhosis is a ‘‘vascular disease’’ characterized by portal hypertension and hyperdynamic syndrome [35]. Damages in liver can result in the reduced blood flow going through the J. Liu Á A. Ahmed Á Y. Ma Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China D. Wu Á X. Li Á Y. Xin (&) Department of Biotechnology, Dalian Medical University, Dalian 116044, China e-mail: jimxin@hotmail.com L. Tang Department of Microecology, Dalian Medical University, Dalian, China D. Mo Department of Laboratory Medicine, The Affiliated Hospital of Chifeng Medical University, Chifeng, China Y. Ma Department of Laboratory Medicine, The Second Affiliated Hospital of Dalian Medical University, Dalian, China 123 Curr Microbiol (2012) 65:7–13 DOI 10.1007/s00284-012-0105-8