As a component of human holobiont system, microbes provide a novel dimension to the understanding of health and diseases that differ across various human populations. Skin is an organ with a dynamic ecosystem that harbours enormous variety of commensal microbes consisting of millions of bacteria, fungi and viruses which constantly communicate amongst each other and with the host immune system. The composition of the human skin microbiome is determined by the genetics, environmental factors, and the local microenvironment. Thus, the human skin microbiota can vary among persons of age, sex, ethnic groups and state of health. The microbiome plays critical roles in the development of major components of the host’s innate and adaptive immune system, while the immune system orchestrates the maintenance of host-microbe symbiosis. Skin and its microbiota have evolved to remain in homeostasis. However, frequently perturbations to normal skin homeostasis can be facilitated by a variety of factors such as environmental stress, diet, genetic mutations, and the microbiome itself that results into microbial dysbiosis and increase susceptibility to diseases. The preponderance of current researches show that skin microbiome is vital in inflammation modulation and speculate a relationship between commensal microbial species on inflammation and thus eventual skin malignancy. 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 genotoxin stress of UVR, other risk factors, including immune suppression, chronic inflammation, suggest the skin microbiome as an additional, unexplored risk factor and potential disease biomarker. It warrants a comprehensive understanding of relation between skin microbiome and skin cancer which may provide insight into novel skin cancer therapy utilizing microbiota. In this context, this review is an attempt to decipher the intrinsic interaction of skin microbiome with cutaneous immune cells and the mechanisms involved in carcinogenesis.
