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International Journal of Oral Science Mar 2022Oral bacteria directly affect the disease status of dental caries and periodontal diseases. The dynamic oral microbiota cooperates with the host to reflect the... (Review)
Review
Oral bacteria directly affect the disease status of dental caries and periodontal diseases. The dynamic oral microbiota cooperates with the host to reflect the information and status of immunity and metabolism through two-way communication along the oral cavity and the systemic organs. The oral cavity is one of the most important interaction windows between the human body and the environment. The microenvironment at different sites in the oral cavity has different microbial compositions and is regulated by complex signaling, hosts, and external environmental factors. These processes may affect or reflect human health because certain health states seem to be related to the composition of oral bacteria, and the destruction of the microbial community is related to systemic diseases. In this review, we discussed emerging and exciting evidence of complex and important connections between the oral microbes and multiple human systemic diseases, and the possible contribution of the oral microorganisms to systemic diseases. This review aims to enhance the interest to oral microbes on the whole human body, and also improve clinician's understanding of the role of oral microbes in systemic diseases. Microbial research in dentistry potentially enhances our knowledge of the pathogenic mechanisms of oral diseases, and at the same time, continuous advances in this frontier field may lead to a tangible impact on human health.
Topics: Bacteria; Dental Caries; Humans; Microbiota; Mouth; Mouth Diseases; Periodontal Diseases
PubMed: 35236828
DOI: 10.1038/s41368-022-00163-7 -
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 -
Nature Reviews. Microbiology Feb 2024The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and... (Review)
Review
The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and highly structured biogeography that shapes metabolic exchange on a local scale and results from the diverse microenvironments present in the oral cavity. The oral microbiota also interfaces with the immune system of the human host and has an important role in not only the health of the oral cavity but also systemic health. In this Review, we highlight recent advances including novel insights into the biogeography of several oral niches at the species level, as well as the ecological role of candidate phyla radiation bacteria and non-bacterial members of the oral microbiome. In addition, we summarize the relationship between the oral microbiota and the pathology of oral diseases and systemic diseases. Together, these advances move the field towards a more holistic understanding of the oral microbiota and its role in health, which in turn opens the door to the study of novel preventive and therapeutic strategies.
Topics: Humans; Microbiota; Mouth; Bacteria; Archaea; Viruses
PubMed: 37700024
DOI: 10.1038/s41579-023-00963-6 -
Head and Neck Pathology Sep 2019Leukoplakia and erythroplakia are two entities under the moniker of "oral potentially malignant disorders" that are highly associated with the presence of oral... (Review)
Review
Leukoplakia and erythroplakia are two entities under the moniker of "oral potentially malignant disorders" that are highly associated with the presence of oral epithelial dysplasia (OED) at first biopsy, while lesions of submucous fibrosis develop OED after being present for years. Importantly, traumatic/frictional keratoses are often mistaken clinically for leukoplakia and it is important for the pathologist to recognize and report them as such. The features of OED have been well-described and other architectural features will be discussed here, in particular verrucous and papillary architecture, bulky epithelial proliferation and epithelial atrophy. Proliferative leukoplakia, verrucous or otherwise, often show only hyperkeratosis in early lesions, with development of OED occurring over time, and squamous cell carcinoma developing in the majority of cases over time. The concept of hyperkeratosis without features of OED and that is not reactive, is likely a precursor to the dysplastic phenotype. Many cases of leukoplakia exhibiting OED are associated with a band of lymphocytes at the interface and these should not be mistaken for oral lichen planus.
Topics: Humans; Leukoplakia, Oral; Mouth Mucosa
PubMed: 30887394
DOI: 10.1007/s12105-019-01020-6 -
Actas Dermo-sifiliograficas 2020Recurrent aphthous stomatitis is a chronic inflammatory disease of the oral mucosa. It is characterized by painful mouth ulcers that cannot be explained by an underlying... (Review)
Review
Recurrent aphthous stomatitis is a chronic inflammatory disease of the oral mucosa. It is characterized by painful mouth ulcers that cannot be explained by an underlying disease. Recurrent oral mucosal ulcers require a proper differential diagnosis to rule out other possible causes before recurrent aphthous stomatitis is diagnosed. The condition is common, with prevalence rates ranging from 5 to 60% in different series. Its pathogenesis is unknown, but multiple factors are considered to play a part. There are no standardized treatments for this condition and none of the treatments are curative. The goal of any treatment should be to alleviate pain, reduce the duration of ulcers, and prevent recurrence.
Topics: Humans; Mouth Mucosa; Oral Ulcer; Pain; Recurrence; Stomatitis, Aphthous
PubMed: 32451064
DOI: 10.1016/j.ad.2019.09.004 -
Translational Research : the Journal of... Oct 2021There is significant interest in understanding the cellular mechanisms responsible for expedited healing response in various oral tissues and how they are impacted by... (Review)
Review
There is significant interest in understanding the cellular mechanisms responsible for expedited healing response in various oral tissues and how they are impacted by systemic diseases. Depending upon the types of oral tissue, wound healing may occur by predominantly re-eptihelialization, by re-epithelialization with substantial new connective tissue formation, or by a a combination of both plus new bone formation. As a result, the cells involved differ and are impacted by systemic diaseses in various ways. Diabetes mellitus is a prevalent metabolic disorder that impairs barrier function and healing responses throughout the human body. In the oral cavity, diabetes is a known risk factor for exacerbated periodontal disease and delayed wound healing, which includes both soft and hard tissue components. Here, we review the mechanisms of diabetic oral wound healing, particularly on impaired keratinocyte proliferation and migration, altered level of inflammation, and reduced formation of new connective tissue and bone. In particular, diabetes inhibits the expression of mitogenic growth factors whereas that of pro-inflammatory cytokines is elevated through epigenetic mechanisms. Moreover, hyperglycemia and oxidative stress induced by diabetes prevents the expansion of mesengenic cells that are involved in both soft and hard tissue oral wounds. A better understanding of how diabetes influences the healing processes is crucial for the prevention and treatment of diabetes-associated oral complications.
Topics: Animals; Comorbidity; Diabetes Mellitus; Humans; Mouth; Re-Epithelialization; Tooth Extraction; Wound Healing
PubMed: 33992825
DOI: 10.1016/j.trsl.2021.05.001 -
Scientific Reports Aug 2021Understanding changes in oral flora during pregnancy, its association to maternal health, and its implications to birth outcomes is essential. We searched PubMed,... (Meta-Analysis)
Meta-Analysis
Understanding changes in oral flora during pregnancy, its association to maternal health, and its implications to birth outcomes is essential. We searched PubMed, Embase, Web of Science, and Cochrane Library in May 2020 (updated search in April and June 2021), and conducted a systematic review and meta-analyses to assess the followings: (1) oral microflora changes throughout pregnancy, (2) association between oral microorganisms during pregnancy and maternal oral/systemic conditions, and (3) implications of oral microorganisms during pregnancy on birth outcomes. From 3983 records, 78 studies were included for qualitative assessment, and 13 studies were included in meta-analysis. The oral microflora remains relatively stable during pregnancy; however, pregnancy was associated with distinct composition/abundance of oral microorganisms when compared to postpartum/non-pregnant status. Oral microflora during pregnancy appears to be influenced by oral and systemic conditions (e.g. gestational diabetes mellitus, pre-eclampsia, etc.). Prenatal dental care reduced the carriage of oral pathogens (e.g. Streptococcus mutans). The Porphyromonas gingivalis in subgingival plaque was more abundant in women with preterm birth. Given the results from meta-analyses were inconclusive since limited studies reported outcomes on the same measuring scale, more future studies are needed to elucidate the association between pregnancy oral microbiota and maternal oral/systemic health and birth outcomes.
Topics: Female; Humans; Microbiota; Mouth; Periodontal Diseases; Pregnancy; Pregnancy Outcome; Premature Birth; Publication Bias; Risk
PubMed: 34413437
DOI: 10.1038/s41598-021-96495-1 -
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 Cellular and Infection... 2023Oral diseases are among the most common diseases around the world that people usually suffer from during their lifetime. Tooth decay is a multifactorial disease, and the... (Review)
Review
Oral diseases are among the most common diseases around the world that people usually suffer from during their lifetime. Tooth decay is a multifactorial disease, and the composition of oral microbiota is a critical factor in its development. Also, is considered the most important caries-causing species. It is expected that probiotics, as they adjust the intestinal microbiota and reduce the number of pathogenic bacteria in the human intestine, can exert their health-giving effects, especially the anti-pathogenic effect, in the oral cavity, which is part of the human gastrointestinal tract. Therefore, numerous and studies have been conducted on the role of probiotics in the prevention of tooth decay. In this review, while investigating the effect of different strains of probiotics and on oral diseases, including dental caries, candida yeast infections, periodontal diseases, and halitosis, we have also discussed postbiotics as novel non-living biological compounds derived from probiotics.
Topics: Humans; Oral Health; Dental Caries; Probiotics; Mouth; Streptococcus mutans
PubMed: 36968114
DOI: 10.3389/fcimb.2023.1120995 -
Cancer Medicine Sep 2020Bacteria identified in the oral cavity are highly complicated. They include approximately 1000 species with a diverse variety of commensal microbes that play crucial... (Review)
Review
Bacteria identified in the oral cavity are highly complicated. They include approximately 1000 species with a diverse variety of commensal microbes that play crucial roles in the health status of individuals. Epidemiological studies related to molecular pathology have revealed that there is a close relationship between oral microbiota and tumor occurrence. Oral microbiota has attracted considerable attention for its role in in-situ or distant tumor progression. Anaerobic oral bacteria with potential pathogenic abilities, especially Fusobacterium nucleatum and Porphyromonas gingivalis, are well studied and have close relationships with various types of carcinomas. Some aerobic bacteria such as Parvimonas are also linked to tumorigenesis. Moreover, human papillomavirus, oral fungi, and parasites are closely associated with oropharyngeal carcinoma. Microbial dysbiosis, colonization, and translocation of oral microbiota are necessary for implementation of carcinogenic functions. Various underlying mechanisms of oral microbiota-induced carcinogenesis have been reported including excessive inflammatory reaction, immunosuppression of host, promotion of malignant transformation, antiapoptotic activity, and secretion of carcinogens. In this review, we have systemically described the impact of oral microbial abnormalities on carcinogenesis and the future directions in this field for bringing in new ideas for effective prevention of tumors.
Topics: Alphapapillomavirus; Bacteria, Aerobic; Bacteria, Anaerobic; Bacterial Translocation; Cell Transformation, Neoplastic; Disease Progression; Dysbiosis; Firmicutes; Fungi; Fusobacterium nucleatum; Humans; Immune Tolerance; Microbiota; Mouth; Neoplasms; Oropharyngeal Neoplasms; Porphyromonas gingivalis
PubMed: 32638533
DOI: 10.1002/cam4.3206