Microbiome-Aware Skincare Through Prebiotic Engineering SECTION 1: ABSTRACT Human skin functions as a vast ecosystem hosting diverse microorganisms that contribute to barrier integrity, immune regulation, and hydration. Disruptions to this microbiome, that can be caused by factors such as harsh surfactants, preservatives, pH imbalance, and environmental stressors, can lead to dysbiosis, a skin condition characterized by increased transepidermal water loss, inflammation, and conditions including acne and atopic dermatitis. New microbiome-friendly cosmetic strategies emphasize restoring microbial balance through prebiotics, probiotics, and postbiotics, yet current skincare approaches remain largely non-personalized and often neglect the important interaction between cosmetic ingredients and the skin’s microbiome. Traditional skincare overlooks the microbiome’s central role in maintaining homeostasis, contributing to a lot of the skin conditions affecting a large proportion of the population.