The Role of Skin and Orogenital Microbiota in Protective Immunity and Chronic Immune-Mediated Inflammatory Disease

Abstract

The skin and orogenital mucosae, which constitute complex protective barriers against infection and injuries, are not only the first to come into contact with pathogens but are also colonized by a set of microorganisms that are essential to maintain a healthy physiological environment. Using 16S ribosomal RNA metagenomic sequencing, scientists recognized that the microorganism colonization has greater diversity and variability than previously assumed. These microorganisms, such as commensal bacteria, affect the host’s immune response against pathogens and modulate chronic inflammatory responses. Previously, a single pathogen was thought to cause a single disease, but current evidence suggests that dysbiosis of the tissue microbiota may underlie the disease status. Dysbiosis results in aberrant immune responses at the surface and furthermore, affects the systemic immune response. Hence, understanding the initial interaction between the barrier surface immune system and local microorganisms is important for understanding the overall systemic effects of the immune response. In this review, we describe current evidence for the basis of the interactions between pathogens, microbiota, and immune cells on surface barriers and offer explanations for how these interactions may lead to chronic inflammatory disorders.

Phenolic and Nonpolar Fractions of Elaeagnus rhamnoides (L.) A. Nelson Extracts as Virulence Modulators—In Vitro Study on Bacteria, Fungi, and Epithelial Cells

“…In the case of SBT products, they have applications in the supportive therapy of local skin lesions, mucosal infections, and associated inflammatory symptoms in wound healing and other conditions [ 8 , 9 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], directions that are in part reflected in the topics of ongoing clinical trials [ 10 ]. However, the sites of possible action of SBT-derived compounds in human body are the niches richly inhabited by many microorganisms constituting natural microbiota, which play a significant role in the host immune system [ 19 , 20 ]. Therefore, the influence of fractionated SBT extracts has been tested on representatives of pathogenic, opportunistic, and commensal microorganisms of the following genera: Staphylococcus , Streptococcus , Helicobacter , Bacillus , Escherichia , Proteus , Pseudomonas , Lactobacillus , Candida .…”

Systematic review about 10 interventions in dermatitis. A document from the Latin American Society of Allergy, Asthma, and Immunology

“…47 During puberty, new changes occur in skin microbiota. 48 There are several mechanisms by which changes in microbial skin diversity (dysbiosis) affect the development of atopic dermatitis; the production, by these dysbiosis bacteria, of several enzymes, such as: proteases (which induce corneocyte desquamation); lipases (which break down lipids of skin barrier); ceramidases (which break down the ceramides present in the barrier structure). 49,50 This bacterial overgrowth, with subsequent biofilm formation and mainly related to the pathogenic strains of Staphylococcus aureus (methicillin-resistant Staphylococcus aureus), would be directly related to changes in the cutaneous barrier.…”

Are Bacteria Infectious Pathogens in Hidradenitis Suppurativa? Debate at the Symposium for Hidradenitis Suppurativa Advances Meeting, November 2017

“…Once in the dermis, these commensals initiate a vigorous host inflammatory response. For unknown genetic, hormonal, and/or environmental reasons, these commensal bacteria could multiply and become pathogenic (Park and Lee, 2017).…”