Scientists from US Marine Biological Laboratory have demonstrated that colorectal cancer tissues may have the feature of biofilms which are produced by bacteria. They identified invasive polymicrobial bacterial biofilms, structures previously associated with nonmalignant intestinal prathology, nearly universally on the right-sided tumors but only 12% of left-sided tumors. This finding was published in PNAS.

Environmental factors clearly affect colorectal cancer (CRC) incidence, but the mechanisms through which these factors function are unknown. One prime candidate is an altered colonic microbiota.

In this study, researchers firstly demonstrate that bacterial biofilms are associated with colorectal cancers. Colonbiofilms, dense communities of bacteria encased in a likely complex matrix that contact the colon epithelial cells, are nearly universal on right colon tumors. Most remarkably, biofilm presence correlates with bacterial tissue invasion and changes in tissue biology with enhanced cellular proliferation, a basic feature of oncogenic transformation occurring even in colons without evidence of cancer. Microbiome profiling revealed that biofilm communities on paired normal mucosa cluster with tumor mrcrobiomes but lack distinct taxa differences

This work introduces a previously unidentified concept whereby mrcrobial community structural organization exhibits the potential to contribute to disease progression.

Reference:

Dejea C M, Wick E C, Hechenbleikner E M, et al. Microbiota organization is a distinct feature of proximal colorectal cancers[J]. Proceedings of the National Academy of Sciences, 2014: 201406199.