title: Gut bacteria in health and disease: a survey on the interface between intestinal microbiology and colorectal cancer.
abstract: A healthy human body contains at least tenfold more bacterial cells than human cells and the most abundant and diverse microbial community resides in the intestinal tract. Intestinal health is not only maintained by the human intestine itself and by dietary factors, but is also largely supported by this resident microbial community. Conversely, however, a large body of evidence supports a relationship between bacteria, bacterial activities and human colorectal cancer. Symbiosis in this multifaceted organ is thus crucial to maintain a healthy balance within the host-diet-microbiota triangle and accordingly, changes in any of these three factors may drive a healthy situation into a state of disease. In this review, the factors that sustain health or drive this complex intestinal system into dysbiosis are discussed. Emphasis is on the role of the intestinal microbiota and related mechanisms that can drive the initiation and progression of sporadic colorectal cancer (CRC). These mechanisms comprise the induction of pro-inflammatory and pro-carcinogenic pathways in epithelial cells as well as the production of (geno)toxins and the conversion of pro-carcinogenic dietary factors into carcinogens. A thorough understanding of these processes will provide leads for future research and may ultimately aid in development of new strategies for CRC diagnosis and prevention.
authors.affiliation: Department of Laboratory Medicine, Nijmegen Institute for Infection, Inflammation and Immunity (N4i) & Radboud University Centre for Oncology (RUCO) of the Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Boleij
authors.forename: Harold
authors.initials: H
authors.lastname: Tjalsma
mesh_terms: D015179:Colorectal Neoplasms / Q000382:microbiology*; D004032:Diet; D005767:Gastrointestinal Diseases / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D009093:Mucus