Living in Your Skin: Microbes, Molecules, and Mechanisms

Abstract

Human skin functions as a physical, chemical, and immune barrier against the external environment while also providing a protective niche for its resident microbiota, known as the skin microbiome. Cooperation between the microbiota, host skin cells, and the immune system is responsible for maintenance of skin health, and a disruption to this delicate balance, such as by pathogen invasion or a breach in the skin barrier, may lead to impaired skin function. In this minireview, we describe the role of the microbiome in microbe, host, and immune interactions under distinct skin states, including homeostasis, tissue repair, and wound infection. Furthermore, we highlight the growing number of diverse microbial metabolites and products that have been identified to mediate these interactions, particularly those involved in host-microbe communication and defensive symbiosis. We also address the contextual pathogenicity exhibited by many skin commensals and provide insight into future directions in the skin microbiome field.

Hallmarks of Cancer: New Dimensions

“…There are evidently organ/tissue-specific differences in the constitution of the associated microbiomes in homeostasis, aging, and cancer, with both overlapping and distinctive species and abundancies to that of the colon (104,105). Moreover, association studies are providing increasing evidence that local tumorantagonizing/protective versus tumor-promoting tissue microbiomes, similarly to the gut microbiome, can modulate susceptibility and pathogenesis to human cancers arising in their associated organs (106)(107)(108)(109).…”

Needles in haystacks: reevaluating old paradigms for the discovery of bacterial secondary metabolites

“…106 Other natural products shape competitive landscapes other body sites. [106][107][108][109][110] In a remarkable project at Yale University, Strobel and Bascom-Slack engaged undergraduate students in scientic research through a course that involved a eld trip to the Equadorian rainforest to isolate fungi from plants and screen them for biological activities upon return to the lab. 74 The project explored several novelties-fungi, which have been less well combed than bacteria for natural products; Equador's rainforest, which is inaccessible to most researchers; and endophytes, which reside inside plant stems.…”

Microbiome First Approaches to Rescue Public Health and Reduce Human Suffering

“…Starting with the skin, the largest organ in the body, there are commensal microbes that both regulate the health of the skin barrier and provide colonization resistance against pathogenic bacteria and viruses. Skin commensals influence cutaneous immune cells affecting the balance of immune inflammation and wound repair as well as innate immunity against vaccine viruses [78]. Clearly, skin commensals offer a manageable and useful strategy to ensure natural protection against pathogens entering via the skin as well as improper immune inflammatory responses.…”