Our skin, beyond being a physical barrier, hosts a diverse community of microorganisms known as the skin microbiota. “Biotics” have gained attention for their potential to enhance the skin’s health, though their exact mode of action is still unclear. MS-based metabolomics has emerged as a powerful tool to characterize the chemical composition of the skin surface and correlate it with microbial communities. Using CSI:FingerID, researchers identified changes in the skin metabolome that are more pronounced than changes in the microbial composition, suggesting that even subtle shifts in microbial abundance can lead to significant effects on the skin.