Role of Oral Microbiota in Carcinogenesis: A Short Review

Abstract

A strong and healthy microbiome is responsible for homeostasis between the host and microbiota which is necessary to achieve the normal functioning of the body. Dysbiosis provokes prevalence of pathogenic microbes, leading to alterations in gene expression profiles and metabolic processes. This in turn results in anomalous immune responses of the host. Dysbiosis may be associated with a wide variety of diseases like irritable bowel syndrome, coeliac disease, allergic conditions, bronchitis, asthma, heart diseases and oncogenesis. Presently, the links between oral microbial consortia and their functions, not only in the preservation of homeostasis but also pathogenesis of several malignancies have gained much awareness from the scientific community. The primary intent of this review is to highlight the dynamic role of oral microbiome in oncogenesis and its progression through various mechanisms. A literature search was conducted using multiple databases comprising of PubMed, Scopus, Google Scholar, and Cochrane electronic databases with keywords including microbiome, microbiota, carcinogenesis, tumorigenesis, and immunosuppression. Current and the past literature has pointed out the role of microorganisms in oncogenesis. It may be put forth that both the commensal and pathogenic strains of oral microbiome play an undeniably conspicuous role in carcinogenesis at different body sites.

The ways Fusobacterium nucleatum translocate to breast tissue and contribute to breast cancer development

“…As research studies have confirmed the prevalence of Fusobacterium genera in the human breast cancer microbial community (Issrani et al., 2022; Tzeng et al., 2021), a growing awareness is whether F. nucleatum accelerates breast tumor progression through immunomodulation and other mechanisms as in colon cancer. Parhi et al.…”

“…A supporting analysis by Tzeng et al (2021) reported that Porphyromonas and Fusobacterium accounted for higher proportion in breast cancers with higher tumor stage. Issrani et al (2022) summarized that breast cancers were correlated with Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, and Prevotella spp. However, no study has yet elucidated the specific mechanisms of these microorganisms in carcinogenesis.…”

“…As research studies have confirmed the prevalence of Fusobacterium genera in the human breast cancer microbial community (Issrani et al, 2022;Tzeng et al, 2021), a growing awareness is whether F. nucleatum accelerates breast tumor progression through immunomodulation and other mechanisms as in colon cancer. Parhi et al (2020) found that the majority of breast tumor samples detected F. nucleatum showed high galactose (Gal)-N-acetylgalactosamine (GalNAc) levels, hypothesizing that fusobacterium autotransporter protein 2 (Fap2)-Gal-GalNAc interaction contributed to the intratumoral colonization of Fusobacterium.…”

“…Issrani et al. (2022) summarized that breast cancers were correlated with Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, and Prevotella spp. However, no study has yet elucidated the specific mechanisms of these microorganisms in carcinogenesis.…”

Microbiomes, Their Function, and Cancer: How Metatranscriptomics Can Close the Knowledge Gap

“…Interestingly, while the modern world saw a substantial decrease in smoking prevalence, this decrease did not lead to a decline in oral cancer occurrence [ 84 , 85 ]. Thus, other factors play a significant role in OSCC etiology, including carcinogenic or reactive oxygen species-producing microbiota [ 86 ].…”