Topical treatment interventions elicit personalized and site-specific shifts in human skin bacterial communities

The skin microbiome represents a significant contributor to cutaneous health and disease. This includes its roles in immune tolerance and defense against pathogenic microorganisms. Despite these critical functions, the impact of topical interventions meant to disrupt these communities remains poorly understood. In this study, we present the effects of three clinically-relevant antiseptics, alcohol, povidone-iodine (Betadine), and chlorhexidine, on cutaneous bacterial populations. We illustrate a proficiency of these treatments in altering skin bacterial communities, a result which was highly dependent on interpersonal and body site-specific signatures. We also show that the magnitude of this response can be influenced by both the identity and relative abundances of bacterial inhabitants. By comparing the effects of antiseptic regimens, we highlight the importance of antibacterial activity and mechanical clearance to treatment disruption. We also demonstrate the potential for pre-treatment communities to inform post-treatment response. In all, these results further our understanding of treatment-derived perturbations to the skin microbiota, and establish the ability of topical interventions to influence skin bacterial dynamics.