title: Co-occurrence of driver and passenger bacteria in human colorectal cancer.
abstract: BACKGROUND
  Both genetic and epigenetic alterations have been reported to act as driving forces of tumorigenesis in colorectal cancer (CRC), but a growing body of evidence suggests that intestinal microbiota may be an aetiological factor in the initiation and progression of CRC. Recently, the "driver-passenger" model for CRC has connected these different factors, but little has been done to characterize the CRC gut microbiome.
  
  
  RESULTS
  Building on the driver-passenger model, we used 454 pyrosequencing of bacterial 16S rRNA genes associated with 10 normal, 10 adenoma, and 8 tumor biopsy samples, and found 7 potential driver bacterial genera and 12 potential passenger bacterial genera (7 being pro-inflammatory and 5 anti-inflammatory). Further analysis also showed certain co-expression patterns among different clusters of bacteria that may potentially be related to the promotion or progression of gut cancers.
  
  
  CONCLUSIONS
  The present findings provide preliminary experimental evidence supporting the proposition of bacterial "driver-passenger model" for CRC, and identified potentially novel microbial agents that may be connected to risk of CRC in a Han Chinese population.
authors.affiliation: Department of Infectious Diseases, The First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Geng
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Qingfang
authors.initials: Q
authors.lastname: Song
authors.affiliation: Department of Gastroenterology, The First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Infectious Diseases, The First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Gastroenterology, The First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Fan
authors.affiliation: Medical Faculty, Kunming University of Science and Technology, Kunming 650500, China.
authors.forename: Hailing
authors.initials: H
authors.lastname: Peng
authors.affiliation: Department of Gastroenterology, The First People's Hospital of Yunnan Province, Kunming 650032, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Laboratory of Evolutionary & Functional Genomics, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
keywords: CRC; Co-occurrence; Driver bacteria; Passenger bacteria