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Surgical Oncology Clinics of North... Jul 2015Cancer of the oral cavity is one of the most common malignancies worldwide. Although early diagnosis is relatively easy, presentation with advanced disease is not... (Review)
Review
Cancer of the oral cavity is one of the most common malignancies worldwide. Although early diagnosis is relatively easy, presentation with advanced disease is not uncommon. The standard of care is primary surgical resection with or without postoperative adjuvant therapy. Improvements in surgical techniques combined with the routine use of postoperative radiation or chemoradiation therapy have resulted in improved survival. Successful treatment is predicated on multidisciplinary treatment strategies to maximize oncologic control and minimize impact of therapy on form and function. Prevention of oral cancer requires better education about lifestyle-related risk factors, and improved awareness and tools for early diagnosis.
Topics: Combined Modality Therapy; Humans; Mouth; Mouth Neoplasms; Prognosis
PubMed: 25979396
DOI: 10.1016/j.soc.2015.03.006 -
Pathobiology : Journal of... 2021Oral 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... (Review)
Review
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 Porphyromonas gingivalis and Fusobacterium nucleatum, 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.
Topics: Animals; Carcinogenesis; Inflammation; Mice; Microbiota; Mouth; Neoplasms; Periodontitis
PubMed: 33176328
DOI: 10.1159/000510979 -
Protein & Cell May 2018Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and... (Review)
Review
Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and interaction of variable oral microorganisms help human body against invasion of undesirable stimulation outside. However, imbalance of microbial flora contributes to oral diseases and systemic diseases. Oral microbiomes play an important role in the human microbial community and human health. The use of recently developed molecular methods has greatly expanded our knowledge of the composition and function of the oral microbiome in health and disease. Studies in oral microbiomes and their interactions with microbiomes in variable body sites and variable health condition are critical in our cognition of our body and how to make effect on human health improvement.
Topics: Human Body; Humans; Microbiota; Mouth; Mouth Diseases
PubMed: 29736705
DOI: 10.1007/s13238-018-0548-1 -
International Journal of Oral Science Apr 2020The human microbiome functions as an intricate and coordinated microbial network, residing throughout the mucosal surfaces of the skin, oral cavity, gastrointestinal... (Review)
Review
The human microbiome functions as an intricate and coordinated microbial network, residing throughout the mucosal surfaces of the skin, oral cavity, gastrointestinal tract, respiratory tract, and reproductive system. The oral microbiome encompasses a highly diverse microbiota, consisting of over 700 microorganisms, including bacteria, fungi, and viruses. As our understanding of the relationship between the oral microbiome and human health has evolved, we have identified a diverse array of oral and systemic diseases associated with this microbial community, including but not limited to caries, periodontal diseases, oral cancer, colorectal cancer, pancreatic cancer, and inflammatory bowel syndrome. The potential predictive relationship between the oral microbiota and these human diseases suggests that the oral cavity is an ideal site for disease diagnosis and development of rapid point-of-care tests. The oral cavity is easily accessible with a non-invasive collection of biological samples. We can envision a future where early life salivary diagnostic tools will be used to predict and prevent future disease via analyzing and shaping the infant's oral microbiome. In this review, we present evidence for the establishment of the oral microbiome during early childhood, the capability of using childhood oral microbiome to predict future oral and systemic diseases, and the limitations of the current evidence.
Topics: Child; Child Health; Humans; Infant; Microbiota; Mouth
PubMed: 32350240
DOI: 10.1038/s41368-020-0082-x -
Frontiers in Immunology 2021The oral microbiome, one of the most complex and intensive microbial ecosystems in the human body, comprises bacteria, archaea, fungi, protozoa, and viruses. Dysbiosis... (Review)
Review
The oral microbiome, one of the most complex and intensive microbial ecosystems in the human body, comprises bacteria, archaea, fungi, protozoa, and viruses. Dysbiosis of the oral microbiome is the initiating factor that leads to oral infectious diseases. Infection is a sophisticated biological process involving interplay between the pathogen and the host, which often leads to activation of programmed cell death. Studies suggest that pyroptosis, apoptosis, and necroptosis are involved in multiple oral infectious diseases. Further understanding of crosstalk between cell death pathways has led to pyroptosis, apoptosis, and necroptosis being integrated into a single term: PANoptosis. PANoptosis is a multifaceted agent of the immune response that has important pathophysiological relevance to infectious diseases, autoimmunity, and cancer. As such, it plays an important role in innate immune cells that detect and eliminate intracellular pathogens. In addition to the classical model of influenza virus-infected and -infected macrophages, other studies have expanded the scope of PANoptosis to include other microorganisms, as well as potential roles in cell types other than macrophages. In this review, we will summarize the pathophysiological mechanisms underlying inflammation and tissue destruction caused by oral pathogens. We present an overview of different pathogens that may induce activation of PANoptosis, along with the functional consequences of PANoptosis in the context of oral infectious diseases. To advance our understanding of immunology, we also explore the strategies used by microbes that enable immune evasion and replication within host cells. Improved understanding of the interplay between the host and pathogen through PANoptosis will direct development of therapeutic strategies that target oral infectious diseases.
Topics: Animals; Antimicrobial Peptides; Apoptosis; Apoptosis Regulatory Proteins; Communicable Diseases; Dysbiosis; Host-Pathogen Interactions; Humans; Inflammation Mediators; Microbiota; Mouth; Mouth Diseases; Necroptosis; Pyroptosis; Signal Transduction
PubMed: 34970269
DOI: 10.3389/fimmu.2021.789610 -
British Dental Journal Nov 2016For millions of years, our resident microbes have coevolved and coexisted with us in a mostly harmonious symbiotic relationship. We are not distinct entities from our...
For millions of years, our resident microbes have coevolved and coexisted with us in a mostly harmonious symbiotic relationship. We are not distinct entities from our microbiome, but together we form a 'superorganism' or holobiont, with the microbiome playing a significant role in our physiology and health. The mouth houses the second most diverse microbial community in the body, harbouring over 700 species of bacteria that colonise the hard surfaces of teeth and the soft tissues of the oral mucosa. Through recent advances in technology, we have started to unravel the complexities of the oral microbiome and gained new insights into its role during both health and disease. Perturbations of the oral microbiome through modern-day lifestyles can have detrimental consequences for our general and oral health. In dysbiosis, the finely-tuned equilibrium of the oral ecosystem is disrupted, allowing disease-promoting bacteria to manifest and cause conditions such as caries, gingivitis and periodontitis. For practitioners and patients alike, promoting a balanced microbiome is therefore important to effectively maintain or restore oral health. This article aims to give an update on our current knowledge of the oral microbiome in health and disease and to discuss implications for modern-day oral healthcare.
Topics: Dental Caries; Humans; Microbiota; Mouth; Oral Health; Periodontitis
PubMed: 27857087
DOI: 10.1038/sj.bdj.2016.865 -
BioMed Research International 2016
Topics: Animals; Biocompatible Materials; Dental Pulp Cavity; Humans; Lasers; Mouth; Mouth Diseases; Mouth Mucosa
PubMed: 27635397
DOI: 10.1155/2016/2849795 -
Microbiome Apr 2019Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer... (Observational Study)
Observational Study
BACKGROUND
Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer chemotherapy. Although antineoplastic cytotoxicity constitutes the primary injury trigger, the interaction of oral microbial commensals with mucosal tissues could modify the response. It is not clear, however, whether chemotherapy and its associated treatments affect oral microbial communities disrupting the homeostatic balance between resident microorganisms and the adjacent mucosa and if such alterations are associated with mucositis. To gain knowledge on the pathophysiology of oral mucositis, 49 subjects receiving 5-fluorouracil (5-FU) or doxorubicin-based chemotherapy were evaluated longitudinally during one cycle, assessing clinical outcomes, bacterial and fungal oral microbiome changes, and epithelial transcriptome responses. As a control for microbiome stability, 30 non-cancer subjects were longitudinally assessed. Through complementary in vitro assays, we also evaluated the antibacterial potential of 5-FU on oral microorganisms and the interaction of commensals with oral epithelial tissues.
RESULTS
Oral mucositis severity was associated with 5-FU, increased salivary flow, and higher oral granulocyte counts. The oral bacteriome was disrupted during chemotherapy and while antibiotic and acid inhibitor intake contributed to these changes, bacteriome disruptions were also correlated with antineoplastics and independently and strongly associated with oral mucositis severity. Mucositis-associated bacteriome shifts included depletion of common health-associated commensals from the genera Streptococcus, Actinomyces, Gemella, Granulicatella, and Veillonella and enrichment of Gram-negative bacteria such as Fusobacterium nucleatum and Prevotella oris. Shifts could not be explained by a direct antibacterial effect of 5-FU, but rather resembled the inflammation-associated dysbiotic shifts seen in other oral conditions. Epithelial transcriptional responses during chemotherapy included upregulation of genes involved in innate immunity and apoptosis. Using a multilayer epithelial construct, we show mucositis-associated dysbiotic shifts may contribute to aggravate mucosal damage since the mucositis-depleted Streptococcus salivarius was tolerated as a commensal, while the mucositis-enriched F. nucleatum displayed pro-inflammatory and pro-apoptotic capacity.
CONCLUSIONS
Altogether, our work reveals that chemotherapy-induced oral mucositis is associated with bacterial dysbiosis and demonstrates the potential for dysbiotic shifts to aggravate antineoplastic-induced epithelial injury. These findings suggest that control of oral bacterial dysbiosis could represent a novel preventive approach to ameliorate oral mucositis.
Topics: Antineoplastic Agents; Bacteria; Drug Therapy; Drug-Related Side Effects and Adverse Reactions; Dysbiosis; Fluorouracil; Fungi; Humans; Inflammation; Longitudinal Studies; Microbiota; Mouth; Mouth Mucosa; Prospective Studies; Stomatitis
PubMed: 31018870
DOI: 10.1186/s40168-019-0679-5 -
Wiley Interdisciplinary Reviews.... Sep 2017A mouth is present in all animals, and comprises an opening from the outside into the oral cavity and the beginnings of the digestive tract to allow eating. This review... (Review)
Review
A mouth is present in all animals, and comprises an opening from the outside into the oral cavity and the beginnings of the digestive tract to allow eating. This review focuses on the earliest steps in mouth formation. In the first half, we conclude that the mouth arose once during evolution. In all animals, the mouth forms from ectoderm and endoderm. A direct association of oral ectoderm and digestive endoderm is present even in triploblastic animals, and in chordates, this region is known as the extreme anterior domain (EAD). Further support for a single origin of the mouth is a conserved set of genes that form a 'mouth gene program' including foxA and otx2. In the second half of this review, we discuss steps involved in vertebrate mouth formation, using the frog Xenopus as a model. The vertebrate mouth derives from oral ectoderm from the anterior neural ridge, pharyngeal endoderm and cranial neural crest (NC). Vertebrates form a mouth by breaking through the body covering in a precise sequence including specification of EAD ectoderm and endoderm as well as NC, formation of a 'pre-mouth array,' basement membrane dissolution, stomodeum formation, and buccopharyngeal membrane perforation. In Xenopus, the EAD is also a craniofacial organizer that guides NC, while reciprocally, the NC signals to the EAD to elicit its morphogenesis into a pre-mouth array. Human mouth anomalies are prevalent and are affected by genetic and environmental factors, with understanding guided in part by use of animal models. WIREs Dev Biol 2017, 6:e275. doi: 10.1002/wdev.275 For further resources related to this article, please visit the WIREs website.
Topics: Animals; Ectoderm; Endoderm; Gene Expression Regulation, Developmental; Humans; Mouth; Neural Crest; Xenopus
PubMed: 28514120
DOI: 10.1002/wdev.275 -
Journal of Dentistry Jan 2019To provide an update on our current understanding of how saliva and its various constituents directly and indirectly affect oral bacteria and thereby play a role in the...
OBJECTIVES
To provide an update on our current understanding of how saliva and its various constituents directly and indirectly affect oral bacteria and thereby play a role in the modulation and maintenance of a healthy oral microbiota and also the associations with symbiosis and dysbiosis.
METHODS
The search for biomedical literature on saliva and its antimicrobial activities (years 1966 to 2017) was conducted in PubMed, Embase and Web of Science databases.
RESULTS
This review underlines that saliva plays an essential role in shaping and maintaining the ecological equilibrium of the resident oral microbiota. Saliva contributes to the formation of the salivary pellicle, which covers the oral hard and soft tissues, and thereby determines the initial adhesion and colonisation of microorganisms. Saliva facilitates clearance of dietary carbohydrates and microorganisms from the oral cavity, but also supplies bacteria with nutrients through enzymatic breakdown of dietary starch and proteins and salivary glycoproteins. In addition, saliva comprises proteins such as mucins, which block the adherence of certain microorganisms to oral surfaces through binding and aggregating mechanisms. Saliva also provides antimicrobial activity through numerous proteins and peptides including mucins, lactoferrin, lysozyme, lactoperoxidase, statherin, histatins and secretory immunoglobulin A.
CONCLUSIONS
A balanced oral microbiome is important for the maintenance of oral health and symbiosis. Conditions associated with salivary gland hypofunction, impaired oral clearance, low salivary pH and altered salivary composition, often lead to perturbation of the function and composition of the oral microbiome causing dysbiosis, and an associated risk of oral disease.
CLINICAL SIGNIFICANCE
Saliva plays a significant role in keeping the relationship between the host and oral microbiota in a symbiotic state. In conditions with salivary gland dysfunction, the natural balance of the oral microbiome is often disturbed, leading to dysbiosis and associated risks of gingivitis, caries and fungal infection.
Topics: Dental Pellicle; Immunoglobulin A, Secretory; Microbiota; Mouth; Saliva; Salivary Proteins and Peptides
PubMed: 30696553
DOI: 10.1016/j.jdent.2018.08.010