Oral Microbiota and Cancer Development

Abstract

Oral microbiota are among the most diverse in the human body. More than 700 species have been identified in the mouth, and new sequencing methods are allowing us to discover even more species. The anatomy of the oral cavity is different from that of other body sites. The oral cavity has mucosal surfaces (the tongue, the buccal mucosa, the gingiva, and the palate), hard tissues (the teeth), and exocrine gland tissue (major and minor salivary glands), all of which present unique features for microbiota composition. The connection between oral microbiota and diseases of the human body has been under intensive research in the past years. Furthermore, oral microbiota have been associated with cancer development. Patients suffering from periodontitis, a common advanced gingival disease caused by bacterial dysbiosis, have a 2–5 times higher risk of acquiring any cancer compared to healthy individuals. Some oral taxa, especially <i>Porphyromonas gingivalis</i> and <i>Fusobacterium nucleatum</i>, have been shown to have carcinogenic potential by several different mechanisms. They can inhibit apoptosis, activate cell proliferation, promote cellular invasion, induce chronic inflammation, and directly produce carcinogens. These microbiota changes can already be seen with potentially malignant lesions of the oral cavity. The causal relationship between microbiota and cancer is complex. It is difficult to accurately study the impact of specific bacteria on carcinoma development in humans. This review focuses on the elucidating the interactions between oral cavity bacterial microbiota and cancer. We gather literature on the current knowledge of the bacterial contribution to cancer development and the mechanisms behind it.

Drug Delivery (Nano)Platforms for Oral and Dental Applications: Tissue Regeneration, Infection Control, and Cancer Management

“…P. gingivalis and F. nucleatum , common pathogens in periodontitis‐affected patients, have carcinogenic potential due to their ability to influence cell apoptosis, activate cell proliferation, and even produce carcinogens. [ 265 ] Oral cancer is considered the major challenge in dental public health because it has high mortality rate. There were 3 54 864 oral cancer cases worldwide in 2018 alone, with up to 177.384 deaths.…”

Distinct Microbial Communities Colonize Tonsillar Squamous Cell Carcinoma

“…Localized chronic in ammation is thought to be one of the major drivers of carcinogenesis [31]. The Gram-negative and invasive bacteria Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis are frequently discussed to be causally involved in the induction of squamous cell carcinoma in the oropharynx [32,33]. F. nucleatum and P. gingivalis have been shown to promote tumor progression in an oropharyngeal squamous cell carcinoma mouse model [34] and F. nucleatum subspecies polymorphum has been found to be signi cantly increased in oral squamous cell carcinoma biopsies [35].…”

The Microbiome and Its Implications in Cancer Immunotherapy

“…Microbes need to be characterized in each kind of cancer, and proper control measures need to be devised for treatment [ 40 , 41 , 42 , 43 ]. Several microbes have been causally linked to various types of cancers, e.g., Helicobacter pylori are the major causative agent of gastric lymphoma, gastric adenocarcinoma, and esophageal adenocarcinoma, while the Epstein–Barr virus (EBV) causes lymphomas and nasopharyngeal carcinoma [ 44 , 45 ]. Other viruses have been reported to cause other types of liver and lymphatic cancers are shown in Table 2 [ 46 ].…”