Interactions between host factors and the skin microbiome

Abstract

The skin is colonized by an assemblage of microorganisms which, for the most part, peacefully coexist with their hosts. In some cases, these communities also provide vital functions to cutaneous health through the modulation of host factors. Recent studies have illuminated the role of anatomical skin site, gender, age, and the immune system in shaping the cutaneous ecosystem. Alterations to microbial communities have also been associated with, and likely contribute to, a number of cutaneous disorders. This review focuses on the host factors that shape and maintain skin microbial communities, and the reciprocal role of microbes in modulating skin immunity. A greater understanding of these interactions is critical to elucidating the forces that shape cutaneous populations and their contributions to skin homeostasis. This knowledge can also inform the tendency of perturbations to predispose and/or bring about certain skin disorders.

Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology

“…Skin is a continuously self-renewing (via repair and desquamation), metabolically active organ providing the means for detoxification of chemical insults; it is immunologically relevant with regard to sensitization and skin allergies, provides a surface that hosts a dense population of microbial commensals (up to 10 7 CFU/cm 2 ) (Peiser et al, 2012;SanMiguel and Grice, 2015), while at the same time protecting the human body against adverse microbial colonization. Furthermore, the skin protects the body from heat (temperature regulation), water (-loss) and electromagnetic radiation.…”

Experimental metagenomics and ribosomal profiling of the human skin microbiome

“…Furthermore, age and gender can be confounding factors that need to be considered and properly addressed. [18][19][20] For these reasons, it is crucial to have properly powered cohorts and ad hoc longitudinal study designs. [21][22][23][24] Propionibacterium acnes and S. epidermidis are two prevalent members of the skin microbiome, but many other bacteria from the Actinobacteria, Firmicutes, Bacteroidetes and Proteobacteria phyla are frequently found.…”

Combined Action of Human Commensal Bacteria and Amorphous Silica Nanoparticles on the Viability and Immune Responses of Dendritic Cells

“…In fact, not only pathogenic microorganisms but also commensal and symbiont microorganisms (organisms making up the microbiome) are especially present in those tissues prone to NP exposure, like the mucosae and the skin. Since the reciprocal interactions between the microbiome and the immune system (22)(23)(24) influence a delicate balance of defensive/proinflammatory and tolerance/anti-inflammatory responses (25)(26)(27)(28)(29)(30), the presence of NPs may represent a factor perturbing host-microbe interactions and, in the end, tissue homeostasis. Such a possibility is indeed suggested by the little evidence that is available: endocytosed NPs and the lipopolysaccharide (LPS) of Gram-negative bacteria synergistically increase the levels of cytokine production by monocytes, macrophages, and DCs (17,(31)(32)(33)(34)(35)(36) and cytotoxicity in A549 epithelial cells (37).…”