Biodiversity of Skin Microbiota as an Important Biomarker for Wound Healing

SIMPLE SUMMARY: Wounded skin can naturally be repaired by a mechanism called wound healing. Human skin is a habitat of various pathogenic and commensal bacteria. While these bacteria are in balance in healthy skin, they can lose the balance by wounding, which leads to delay in the wound-healing process. Moreover, commensal and pathogenic bacteria inhabit skin tissue and have constant communication with the immune system, which can increase and decrease the healing efficiency, respectively. This indicates that cutaneous bacteria have important effects on wound healing. Herein, we discuss some important bacteria (coagulase-negative Staphylococci (CoNS), S. aureus, P. aeruginosa, and Lactobacilli) present in human skin, the effects of communication of bacteria with the immune system and epithelial cells on wound healing, and the identification techniques and manipulation strategies of the bacterial population in wounded skin tissue. ABSTRACT: Cutaneous wound healing is a natural and complex repair process that is implicated within four stages. However, microorganisms (e.g., bacteria) can easily penetrate through the skin tissue from the wound bed, which may lead to disbalance in the skin microbiota. Although commensal and pathogenic bacteria are in equilibrium in normal skin, their imbalance in the wound area can cause the delay or impairment of cutaneous wounds. Moreover, skin microbiota is in constant crosstalk with the immune system and epithelial cells, which has significance for the healing of a wound. Therefore, understanding the major bacteria species in the cutaneous wound as well as their communication with the immune system has gained prominence in a way that allows for the emergence of a new perspective for wound healing. In this review, the major bacteria isolated from skin wounds, the role of the crosstalk between the cutaneous microbiome and immune system to heal wounds, the identification techniques of these bacteria populations, and the applied therapies to manipulate the skin microbiota are investigated.