Role of Oral Microbiota in Cancer Development

Abstract

Nowadays cancer is the second main cause of death in the world. The most known bacterial carcinogen is Helicobacter pylori. Pathogens that can have an impact on cancer development in the gastrointestinal tract are also found in the oral cavity. Some specific species have been identified that correlate strongly with oral cancer, such as Streptococcus sp., Peptostreptococcus sp., Prevotella sp., Fusobacterium sp., Porphyromonas gingivalis, and Capnocytophaga gingivalis. Many works have also shown that the oral periopathogens Fusobacterium nucleatum and Porphyromonas gingivalis play an important role in the development of colorectal and pancreatic cancer. Three mechanisms of action have been suggested in regard to the role of oral microbiota in the pathogenesis of cancer. The first is bacterial stimulation of chronic inflammation. Inflammatory mediators produced in this process cause or facilitate cell proliferation, mutagenesis, oncogene activation, and angiogenesis. The second mechanism attributed to bacteria that may influence the pathogenesis of cancers by affecting cell proliferation is the activation of NF-κB and inhibition of cellular apoptosis. In the third mechanism, bacteria produce some substances that act in a carcinogenic manner. This review presents potentially oncogenic oral bacteria and possible mechanisms of their action on the carcinogenesis of human cells.

Identification of novel mutational signatures in Asian oral squamous cell carcinomas associated with bacterial infections

“…However, some bacteria have been reported to produce toxins able to induce double-strand DNA breaks (van Elsland and Neefjes 2018). For OSCC the association with bacterial infection is well known, but no mutagenic compounds have been reported to be produced by these bacteria (Karpinski 2019).…”

Microbiota Alterations in Gastrointestinal Cancers

“…The human oral cavity harbors a complex microbial community known to contain over 700 species of bacteria, more than half of which have not been cultivated [80]. Even though oral microbiota can play a protective role against pancreatic cancer in a healthy, commensal state, it may also promote malignancy under pathologic conditions, especially while enriched in taxa related to periodontal disease [81,82]. Dysbiosis of oral bacteria resulting from poor oral hygiene, as well as associated diseases such as periodontitis and tooth loss, may promote bacterial translocation and increase the risk of pancreatic cancer [82].…”

Methods for Searching of Potential Beneficial Bacteria and Their Products in Dental Biofilm

“…Bacterial pathogens founded in dental enamel lesions are many times highly pathogenic and cause also systematic diseases like endocarditis, meningitis, pulmonary fibrosis, arthritis, and some findings predict the connection of dental microbiota with cancerogenesis [3,4].…”