Randomized Controlled Study of Bacteriophages in Acne Reveals Efficacy and Novel Mechanism for Promoting Long-Term Skin Health

BACKGROUND: Acne is the most prevalent skin disease globally, with a significant burden and limited therapeutic innovation. Although it has a multifactorial etiology, Cutibacterium acnes (C acnes) overgrowth is a key factor in driving inflammation in acne. Bacteriophages are a novel mechanism that can specifically target C acnes and are found in greater abundance on healthy skin compared to acne-prone skin. OBJECTIVES: To study the safety and efficacy of phages and salicylic acid (SA) in acne, and to analyze their mode of action and effect on microbiome diversity. METHODS: A randomized double-blind placebo-controlled study was conducted on 90 participants for 8 weeks. Males and females 12 to 35 years old with mild to moderate acne were enrolled in placebo, phage, and phage + SA arms. Clinic visits at baseline, week 4, and week 8 collected safety data, VISIA imaging, lesion counts, IGA scores, and microbiome samples. RESULTS: Phage treatment demonstrated an excellent safety profile. Participants in both phage and phage + SA arms showed significant improvement (P<0.05) over baseline at 8 weeks. Phage application resulted in a statistically significant (P<0.05) decrease of C acnes on the skin compared to placebo. Notably, phage use over 8 weeks significantly increased microbiome diversity, a marker of long-term skin health. CONCLUSION: This study shows the potential of bacteriophages to be a highly promising modality with a unique mode of action for the treatment of acne. Beyond short-term lesion improvement, phage-induced enhancement of microbiome diversity suggests potential for durable, long-term skin health benefits.  .