Internal medicine

Microbiome

Bacteria

Colorectal cancer

Gut flora

Carcinogenesis

Bioinformatics

Biology

Microbiology

Cancer

Paleontology

Immunology

Immunity

Dysbiosis

Fusobacterium nucleatum

Bacteroides

Context (archaeology)

Porphyromonas gingivalis

Periodontitis

Fusobacterium

Genetics

Medicine

Immune system

International Journal of Molecular Sciences

The human organism coexists with its microbiota in a symbiotic relationship. These polymicrobial communities are involved in many crucial functions, such as immunity, protection against pathogens, and metabolism of dietary compounds, thus maintaining homeostasis. The oral cavity and the colon, although distant anatomic regions, are both highly colonized by distinct microbiotas. However, studies indicate that oral bacteria are able to disseminate into the colon. This is mostly evident in conditions such as periodontitis, where specific bacteria, namely Fusobacterium nucrelatum and Porphyromonas gingivalis project a pathogenic profile. In the colon these bacteria can alter the composition of the residual microbiota, in the context of complex biofilms, resulting in intestinal dysbiosis. This orally-driven disruption promotes aberrant immune and inflammatory responses, eventually leading to colorectal cancer (CRC) tumorigenesis. Understanding the exact mechanisms of these interactions will yield future opportunities regarding prevention and treatment of CRC.

Oral Bacteria and Intestinal Dysbiosis in Colorectal Cancer