Human Cutaneous Microbiome and Skin Carcinogenesis: An Immunological Conundrum

The advancements of new methods for understanding the microbial world provide an opportunity to re-evaluate the views of biological anthropology and disease epidemiology. Recent developments in microbial research offer a wider comprehension of the pathogenesis of skin malignancy. Current research supports the idea that the skin microbiota is indeed, an unexplored risk factor and a potential biomarker of skin cancer. Skin is an organ with a dynamic ecosystem that harbours trillions of commensal microbes. The composition of the human skin microbiome is determined by genetics, environmental factors, and the local microenvironment. While the microbiome plays a critical role in the development of the host’s innate and adaptive immune system, the immune system in turn orchestrates the maintenance of host-microbe symbiosis. Thus, while skin and its microbiota have evolved to remain in homeostasis, frequent perturbations are facilitated by environmental stress, diet, gene mutations, and the microbiome itself often resulting in microbial dysbiosis and increased susceptibility to diseases. With more than 1.5 million new cases estimated in 2020, skin cancers are the most commonly diagnosed group of cancers worldwide and apart from the genotoxic stress of UVR, other risk factors including immune suppression, and chronic inflammation, suggest the skin microbiome to be an additional, unexplored risk factor and potential disease biomarker. It warrants a comprehensive understanding of the relation between skin microbiome and skin cancer which may provide insight into novel skin cancer therapy utilizing microbiota.

Key words: Skin microbes, Commensals, Pathogen, Inflammation, Skin cancer.