Background: Acne vulgaris is a common skin disorder associated with a dysbiotic skin microbiome. While changes in the skin microbiome profile in acne have been reported, its role in acne pathogenesis and resolution, as well as the potential to rebalance the acne microbiome through facewash products, remain to be elucidated.
Objectives: To investigate the microbiome signatures of participants with acne, at baseline and 4 weeks after intervention with a facewash product containing plant-derived monoterpenes, and 1 week after a regression phase with no product application.
Methods: Volunteers with mild-to-moderate acne or without acne were recruited and balanced by age and gender for the ethics-approved, balanced, 4-week intervention and 1-week regression study. Participants with acne applied a marketed facial cleanser product containing plant-derived monoterpenes twice daily for 4 weeks. Participants without acne used a marketed mild face cleanser as control. Facial buffer scrub samples were taken just before product application (baseline), 4 weeks after product application and a 1-week regression phase for microbiome analysis. The absolute numbers of predominant bacteria Cutibacterium acnes and Staphylococcus epidermidis were determined by quantitative polymerase chain reaction. The facial microbiome profiles were investigated by 16 s V1-V3 amplicon sequencing and analysed using QIIME pipeline and SpiecEasi.
Results: A significant increase was seen in the dominant bacteria burden with reduced microbiome diversity in people with acne compared with those without acne. At the microbiome community level, a notably fragile microbiome connectivity and changes in the dominant skin bacteria subnetwork were seen in individuals with acne. A topical intervention with a facewash containing plant-derived monoterpenes significantly reduced the dominant bacteria burden in acne. The treatment also improved microbiome diversity, as well as the network resiliency. These effects lasted even after stopping the treatment for a week.
Conclusions: Our findings reveal a new dimension in understanding the differences in the acne microbiome and provide new evidence on the use of topical interventions for improving the dysbiotic status of the acne microbiome which could aid in relieving acne symptoms.
Acne is a very common skin condition. It is identified by the presence of blackheads and whiteheads and inflammation spots. Acne ranges from a few spots on the face, neck, back and chest, to a more severe problem with solid painful lumps under the skin. It may cause scarring. It is also associated with significant changes in the skin’s ‘microbiome’. The skin microbiome is the population of microbes, including bacteria, fungi and viruses, that live on the skin. In this study, we wished to investigate changes to the skin’s microbiome in people with acne. We first looked at the characteristics of the skin’s microbiome. We then asked the study participants to use a facewash that contained particular plant-based ingredients. The aim was to see if it helped reduce the symptoms of acne and restore the microbiome profile towards nonacne skin. We found that people with acne had higher levels of certain bacteria on their skin. They also had fewer different types of bacteria on their skin. These bacteria also interacted less with each other. The facewash provided reduced acne symptoms, reduced the levels of the increased bacteria, restored the diversity of bacteria on the skin and improved how they interacted with each other. These beneficial effects were seen for a week after participants stopped using the facewash. These results highlight the role of skin bacteria in the development of acne. They also provide insights into how a particular facewash can ease acne symptoms.
© The Author(s) 2025. Published by Oxford University Press on behalf of British Association of Dermatologists.