Use of a Bacteriophage Lysin to Control Axillary Malodor

ABSTRACT Background Axillary malodor is primarily caused by bacteria, particularly Staphylococcus hominis , which metabolize apocrine secretions into volatile compounds. Traditional deodorants contain antiseptics that can disrupt the skin microbiome and cause irritation. Alternative methods of odor control are being sought but so far without success. We considered bacteriophage lysins, as these can target specific bacteria and thus offer a more microbiome‐friendly alternative. Objectives Thus, we sought to determine efficacy and safety of a recombinant lysin in reducing axillary malodor, and to assess the lysin's effect on the skin microbiome. Methods We conducted a consumer trial to evaluate the efficacy of a proprietary lysin, supported by in vitro and in vivo safety testing as well as microbiome analysis. Results We demonstrated rapid, sustained odor reduction upon application of a lysin, without skin irritancy and preserving the skin microbiome's diversity. With these outcomes, we address a significant consumer concern. Conclusions We present the first clinically effective use of bacteriophage lysins to control axillary malodor in humans. Our study outcomes favor the use of lysins for microbial control in personal care and other applications.