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The Journal of Investigative Dermatology Jun 2017Human skin contains an abundant and diverse population of microbial organisms. Many of these microbes inhabit follicular structures of the skin. Furthermore, numerous... (Review)
Review
Human skin contains an abundant and diverse population of microbial organisms. Many of these microbes inhabit follicular structures of the skin. Furthermore, numerous studies have shown that the interaction of some members of the skin microbiome with host cells will result in changes in cell function. However, estimates of the potential for the microbiome to influence human health through skin have ignored the inner follicular surface, and therefore vastly underestimated the potential of the skin microbiome to have a systemic effect on the human body. By calculating the surface area of follicular and the interfollicular epithelial surface it is shown that skin provides a vast interface for interactions with the microbiome.
Topics: Bacterial Adhesion; Epidermis; Humans; Microbiota; Skin
PubMed: 28395897
DOI: 10.1016/j.jid.2016.11.045 -
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 -
Biomedicine & Pharmacotherapy =... Jul 2022Silica nanoparticles (SiNPs) are composed of silicon dioxide, the most abundant compound on Earth, and are used widely in many applications including the food industry,... (Review)
Review
Silica nanoparticles (SiNPs) are composed of silicon dioxide, the most abundant compound on Earth, and are used widely in many applications including the food industry, synthetic processes, medical diagnosis, and drug delivery due to their controllable particle size, large surface area, and great biocompatibility. Building on basic synthetic methods, convenient and economical strategies have been developed for the synthesis of SiNPs. Numerous studies have assessed the biomedical applications of SiNPs, including the surface and structural modification of SiNPs to target various cancers and diagnose diseases. However, studies on the in vitro and in vivo toxicity of SiNPs remain in the exploratory stage, and the toxicity mechanisms of SiNPs are poorly understood. This review covers recent studies on the biomedical applications of SiNPs, including their uses in drug delivery systems to diagnose and treat various diseases in the human body. SiNP toxicity is discussed in terms of the different systems of the human body and the individual organs in those systems. This comprehensive review includes both fundamental discoveries and exploratory progress in SiNP research that may lead to practical developments in the future.
Topics: Humans; Nanoparticles; Neoplasms; Particle Size; Silicon Dioxide
PubMed: 35594717
DOI: 10.1016/j.biopha.2022.113053 -
Indian Journal of Ophthalmology Apr 2023The endocrine system influences all tissues and cells in the human body. The ocular surface is constantly exposed to circulating hormones and expresses their specific... (Review)
Review
The endocrine system influences all tissues and cells in the human body. The ocular surface is constantly exposed to circulating hormones and expresses their specific receptors. Dry eye disease (DED) is a disorder with multifactorial etiology, and endocrine anomalies are one of the inciting factors. The endocrine anomalies that cause DED include physiological conditions such as menopause, menstrual cycle variations, pathologies such as polycystic ovarian syndrome, androgen resistance, iatrogenic conditions such as contraceptive use, and antiandrogen treatment. This review highlights the status of these hormones in DED along with the mechanism of action of different hormones on the ocular surface structures and the clinical implications of these effects. The influence of androgens, estrogens, and progesterone on the ocular surface tissues, and the implications of androgen-deficient states in DED are also discussed. The physiological and pathological effects of menopause and sex hormone replacement therapy are discussed. The effects of insulin and insulin resistance on the ocular surface and DED, and the growing potential of topical insulin therapeutics for DED are mentioned. Thyroid-associated ophthalmopathy, its impact on the ocular surface, and the tissue effects of thyroid hormone in the context of DED are reviewed. Finally, the potential role of hormonal therapeutics in the management of DED has also been discussed. The compelling evidence suggests that it would be clinically beneficial to consider the possibility of hormonal imbalances and their impact while treating patients with DED.
Topics: Female; Humans; Androgens; Tears; Dry Eye Syndromes; Eye; Insulins
PubMed: 37026259
DOI: 10.4103/IJO.IJO_2887_22 -
Journal of Immunology Research 2020Human body surfaces, such as the skin, intestines, and respiratory and urogenital tracts, are colonized by a large number of microorganisms, including bacteria, fungi,... (Review)
Review
Human body surfaces, such as the skin, intestines, and respiratory and urogenital tracts, are colonized by a large number of microorganisms, including bacteria, fungi, and viruses, with the gut being the most densely and extensively colonized organ. The microbiome plays an essential role in immune system development and tissue homeostasis. Gut microbiota dysbiosis not only modulates the immune responses of the gastrointestinal (GI) tract but also impacts the immunity of distal organs, such as the lung, further affecting lung health and respiratory diseases. Here, we review the recent evidence of the correlations and underlying mechanisms of the relationship between the gut microbiota and common respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), lung cancer, and respiratory infection, and probiotic development as a therapeutic intervention for these diseases.
Topics: Animals; Biomarkers; Disease Susceptibility; Gastrointestinal Microbiome; Genetic Predisposition to Disease; Host-Pathogen Interactions; Humans; Lung; Microbiota; Respiratory Mucosa; Respiratory Tract Diseases
PubMed: 32802893
DOI: 10.1155/2020/2340670 -
Microbiology Spectrum Jun 2017Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and... (Review)
Review
Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and resistance to immune defenses, including elevated body temperatures. Morphogenesis between small round, detachable cells and long, connected cells is the mechanism by which fungi solve problems of locomotion around or through host barriers. Secretion of lytic enzymes, and uptake systems for the released nutrients, are necessary if a fungus is to nutritionally utilize human tissue. Last, the potent human immune system evolved in the interaction with potential fungal pathogens, so few fungi meet all four conditions for a healthy human host. Paradoxically, the advances of modern medicine have made millions of people newly susceptible to fungal infections by disrupting immune defenses. This article explores how different members of four fungal phyla use different strategies to fulfill the four criteria to infect humans: the Entomophthorales, the Mucorales, the Ascomycota, and the Basidiomycota. Unique traits confer human pathogenic potential on various important members of these phyla: pathogenic Onygenales comprising thermal dimorphs such as and ; the spp. that infect immunocompromised as well as healthy humans; and important pathogens of immunocompromised patients-, , and spp. Also discussed are agents of neglected tropical diseases important in global health such as mycetoma and paracoccidiomycosis and common pathogens rarely implicated in serious illness such as dermatophytes. Commensalism is considered, as well as parasitism, in shaping genomes and physiological systems of hosts and fungi during evolution.
Topics: Ascomycota; Basidiomycota; Biological Evolution; Body Temperature; Entomophthorales; Fungi; Host-Pathogen Interactions; Humans; Immunity, Innate; Immunocompromised Host; Mucorales; Mycetoma; Mycoses; Opportunistic Infections; Phylogeny; Virulence
PubMed: 28597822
DOI: 10.1128/microbiolspec.FUNK-0014-2016 -
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 -
Biomedical Journal Feb 2023An ever expanding body of research over the past several decades suggest that directly touching the earth, a practice known as grounding, puts the body into a healing... (Review)
Review
An ever expanding body of research over the past several decades suggest that directly touching the earth, a practice known as grounding, puts the body into a healing state. The natural universe conducts an energy current known as a direct current (DC). This DC circuit of energy flows through everything on our planet, including plants, animals, human beings, and the surface of our entire globe, creating a global electrical circuit. DC energy is also what the living human body uses to function, as everything from the beating of our heart to the movement of our muscles to our brain's ability to think operates using DC energy. The earth's DC energy flows continuously across the earth's crust, and anything conductive that touches the earth becomes part of this natural circuit. Our human bodies, which are highly conductive, join this global electrical circuit whenever we make direct contact with the earth, a practice known as grounding. Medical studies are revealing that by becoming a part of the global electrical circuit, through grounding, the human body enters a profound healing state. As our understanding of the health benefits of grounding continue to deepen, we can begin to use grounding as an intentional healing tool in clinical medicine. Grounding may play a role in not only improving the body's natural ability to function, but may also play a role in the healing of disease and the prevention of disease development in the first place. Studies so far suggest that becoming a part of the earth's global DC circuit enhances our conductive health, which has far reaching implications to all our organ systems that utilize DC energy and conductivity to work, including but not limited to: our central and peripheral nervous system, our musculoskeletal system, and our cardiovascular system. Further research into the healing properties of grounding will help clinicians tailor suggestions for specific health issues, and will help us understand the role of our body's conductivity in the presence of our global electrical circuit.
Topics: Humans; Earth, Planet; Electric Conductivity; Movement
PubMed: 36481428
DOI: 10.1016/j.bj.2022.12.001