-
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 -
Gastroenterologia Y Hepatologia 2021The human body is populated by myriads of microorganisms throughout its surface and in the cavities connected to the outside. The microbial colonisers of the intestine... (Review)
Review
The human body is populated by myriads of microorganisms throughout its surface and in the cavities connected to the outside. The microbial colonisers of the intestine (microbiota) are a functional and non-expendable part of the human organism: they provide genes (microbiome) and additional functions to the resources of our species and participate in multiple physiological processes (somatic development, nutrition, immunity, etc.). Some chronic non-communicable diseases of developed society (atopias, metabolic syndrome, inflammatory diseases, cancer and some behaviour disorders) are associated with dysbiosis: loss of species richness in the intestinal microbiota and deviation from the ancestral microbial environment. Changes in the vertical transmission of the microbiome, the use of antiseptics and antibiotics, and dietary habits in industrialised society appear to be at the origin of dysbiosis. Generating and maintaining diversity in the microbiota is a new clinical target for health promotion and disease prevention.
Topics: Gastrointestinal Microbiome; Humans; Immune System; Neurosecretory Systems
PubMed: 33652061
DOI: 10.1016/j.gastrohep.2021.01.009 -
International Journal of Environmental... Aug 2022In recent years, social media has become part of our lives, even among children. From the beginning of COVID-19 pandemic period, media device and Internet access rapidly... (Review)
Review
In recent years, social media has become part of our lives, even among children. From the beginning of COVID-19 pandemic period, media device and Internet access rapidly increased. Adolescents connected Internet alone, consulting social media, mostly Instagram, TikTok, and YouTube. During "lockdown", the Internet usage allowed communication with peers and the continuity activities such as school teaching. However, we have to keep in mind that media usage may be related to some adverse consequences especially in the most vulnerable people, such as the young. Aim of the review is to focus on risks correlated to social media use by children and adolescents, identifying spies of rising problems and engaging in preventive recommendations. The scoping review was performed according to PRISMA guidelines, searching on PubMed the terms "social media" or "social network", "health", and "pediatrics". Excluding articles not pertinent, we found 68 reports. Out of them, 19 were dealing with depression, 15 with diet, and 15 with psychological problems, which appeared to be the most reported risk of social media use. Other identified associated problems were sleep, addiction, anxiety, sex related issues, behavioral problems, body image, physical activity, online grooming, sight, headache, and dental caries. Public and medical awareness must rise over this topic and new prevention measures must be found, starting with health practitioners, caregivers, and websites/application developers. Pediatricians should be aware of the risks associated to a problematic social media use for the young's health and identify sentinel signs in children as well as prevent negative outcomes in accordance with the family.
Topics: Adolescent; Behavior, Addictive; COVID-19; Child; Dental Caries; Humans; Pandemics; Social Media
PubMed: 36011593
DOI: 10.3390/ijerph19169960 -
Journal of Dental Research Aug 2020More than 100 trillion symbiotic microorganisms constitutively colonize throughout the human body, including the oral cavity, the skin, and the gastrointestinal tract.... (Review)
Review
More than 100 trillion symbiotic microorganisms constitutively colonize throughout the human body, including the oral cavity, the skin, and the gastrointestinal tract. The oral cavity harbors one of the most diverse and abundant microbial communities within the human body, second to the community that resides in the gastrointestinal tract, and is composed of >770 bacterial species. Advances in sequencing technologies help define the precise microbial landscape in our bodies. Environmental and functional differences render the composition of resident microbiota largely distinct between the mouth and the gut and lead to the development of unique microbial ecosystems in the 2 mucosal sites. However, it is apparent that there may be a microbial connection between these 2 mucosal sites in the context of disease pathogenesis. Accumulating evidence indicates that resident oral bacteria can translocate to the gastrointestinal tract through hematogenous and enteral routes. The dissemination of oral microbes to the gut may exacerbate various gastrointestinal diseases, including irritable bowel syndrome, inflammatory bowel disease, and colorectal cancer. However, the precise role that oral microbes play in the extraoral organs, including the gut, remains elusive. Here, we review the recent findings on the dissemination of oral bacteria to the gastrointestinal tract and their possible contribution to the pathogenesis of gastrointestinal diseases. Although little is known about the mechanisms of ectopic colonization of the gut by oral bacteria, we also discuss the potential factors that allow the oral bacteria to colonize the gut.
Topics: Bacteria; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Inflammatory Bowel Diseases; Microbiota; Mouth
PubMed: 32464078
DOI: 10.1177/0022034520924633 -
Journal of Reproductive Immunology Jun 2021The oral cavity contains the second most complex microbial population within the human body, with more than 700 bacterial organisms. Recent advances in Next Generation... (Review)
Review
The oral cavity contains the second most complex microbial population within the human body, with more than 700 bacterial organisms. Recent advances in Next Generation Sequencing technology have unraveled the complexities of the oral microbiome and provided valuable insights into its role in health and disease. The human oral microbiome varies dramatically during the different stages of life, including pregnancy. The total viable microbial counts in pregnant women are known to be higher compared to non-pregnant women, especially in the first trimester of pregnancy. A balanced oral microbiome is vital for a healthy pregnancy, as perturbations in the oral microbiome composition can contribute to pregnancy complications. On the other hand, physiological changes and differences in hormonal levels during pregnancy, increase susceptibility to various oral diseases such as gingivitis and periodontitis. A growing body of evidence supports the link between the composition of the oral microbiome and adverse pregnancy outcomes such as preterm birth, preeclampsia, low birth weight among others. This review aims to summarize the dynamics of oral microbiome during pregnancy and to discuss the relationship between a dysbiotic oral microbiome and pregnancy complications.
Topics: Dysbiosis; Female; Humans; Microbiota; Mouth Mucosa; Oral Health; Oral Hygiene; Periodontitis; Pregnancy; Pregnancy Complications
PubMed: 33676065
DOI: 10.1016/j.jri.2021.103293 -
International Journal of Molecular... Feb 2021The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized... (Review)
Review
The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.
Topics: Animals; Antigens, Neoplasm; Carcinogenesis; Carcinoma, Squamous Cell; Chemokines; Complement System Proteins; Dental Caries; Dental Pulp; Dentin; Fibroblasts; Humans; Intracellular Signaling Peptides and Proteins; Mesenchymal Stem Cells; Mouth Neoplasms; Nerve Net; Neuropeptides; Nitric Oxide; Odontoblasts; Periapical Granuloma; Periapical Periodontitis; Periapical Tissue; Pulpitis; Radicular Cyst
PubMed: 33540711
DOI: 10.3390/ijms22031480 -
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 -
International Journal of Molecular... May 2022The skin, oral cavity, digestive and reproductive tracts of the human body harbor symbiotic and commensal microorganisms living harmoniously with the host. The oral... (Review)
Review
The skin, oral cavity, digestive and reproductive tracts of the human body harbor symbiotic and commensal microorganisms living harmoniously with the host. The oral cavity houses one of the most heterogeneous microbial communities found in the human organism, ranking second in terms of species diversity and complexity only to the gastrointestinal microbiota and including bacteria, archaea, fungi, and viruses. The accumulation of microbial plaque in the oral cavity may lead, in susceptible individuals, to a complex host-mediated inflammatory and immune response representing the primary etiological factor of periodontal damage that occurs in periodontitis. Periodontal disease is a chronic inflammatory condition affecting about 20-50% of people worldwide and manifesting clinically through the detection of gingival inflammation, clinical attachment loss (CAL), radiographic assessed resorption of alveolar bone, periodontal pockets, gingival bleeding upon probing, teeth mobility and their potential loss in advanced stages. This review will evaluate the changes characterizing the oral microbiota in healthy periodontal tissues and those affected by periodontal disease through the evidence present in the literature. An important focus will be placed on the immediate and future impact of these changes on the modulation of the dysbiotic oral microbiome and clinical management of periodontal disease.
Topics: Dysbiosis; Humans; Microbiota; Periodontal Diseases; Periodontitis; Periodontium
PubMed: 35563531
DOI: 10.3390/ijms23095142 -
International Journal of Microbiology 2020The human microbiome comprises bacteria, archaea, viruses, and eukaryotes which reside within and outside our bodies. These organisms impact human physiology, both in... (Review)
Review
The human microbiome comprises bacteria, archaea, viruses, and eukaryotes which reside within and outside our bodies. These organisms impact human physiology, both in health and in disease, contributing to the enhancement or impairment of metabolic and immune functions. Micro-organisms colonise various sites on and in the human body, where they adapt to specific features of each niche. Facultative anaerobes are more dominant in the gastrointestinal tract, whereas strict aerobes inhabit the respiratory tract, nasal cavity, and skin surface. The indigenous organisms in the human body are well adapted to the immune system, due to the biological interaction of the organisms with the immune system over time. An alteration in the intestinal microbial community plays a major role in human health and disease pathogenesis. These alterations result from lifestyle and the presence of an underlying disease. Dysbiosis increases host susceptibility to infection, and the nature of which depends on the anatomical site involved. The unique diversity of the human microbiota accounts for the specific metabolic activities and functions of these micro-organisms within each body site. It is therefore important to understand the microbial composition and activities of the human microbiome as they contribute to health and disease.
PubMed: 32612660
DOI: 10.1155/2020/8045646