From the Guidelines
The primary bacteria associated with acne is Cutibacterium acnes (formerly known as Propionibacterium acnes), a Gram-positive anaerobic rod that plays a significant role in acne pathogenesis. This bacterium is primarily implicated in the development of acne lesions, with some strains likely being pathogenic while others are commensal in the skin 1. The role of C. acnes in acne is supported by the most recent guidelines of care for the management of acne vulgaris, published in the Journal of the American Academy of Dermatology in 2024 1.
Key points to consider when evaluating the relationship between bacteria and acne include:
- The presence of C. acnes in the skin's pores, where it can contribute to the formation of acne lesions
- The role of other bacteria, such as Staphylococcus epidermidis and Corynebacterium species, which can also contribute to acne formation, although to a lesser extent than C. acnes
- The importance of addressing bacterial overgrowth, excess oil production, and dead skin cells in the treatment of acne, as these factors can create an environment conducive to acne development 1.
In clinical practice, understanding the role of C. acnes in acne helps explain why antibiotics and antimicrobial treatments are often effective in managing this common skin condition, and why reducing bacteria, controlling oil production, and exfoliating the skin are key components of many acne treatment regimens 1.
From the Research
Bacteria Associated with Acne
- Cutibacterium acnes (C. acnes), formerly known as Propionibacterium acnes, is recognized as a key factor in acne development, regulating inflammatory and immune pathways 2
- C. acnes is a member of the normal skin microbiota and is frequently isolated from acne lesions 3, 4
- Malassezia spp. have also been linked to acne development through their influence on sebum secretion, comedone formation, and inflammatory response 5
- Staphylococcal strains may exclude acne-associated C. acnes phylotypes, suggesting a potential role for microbial interference in maintaining healthy skin homeostasis 2
Phylotypes of Cutibacterium acnes
- Distinct phylogroups of C. acnes have been discovered, with specific strains associated with human disease 3, 4
- Phylotype IA is the most common type of C. acnes, followed by type IB and type II 3
- There is no significant relationship between C. acnes phylotype and acne severity 3
Role of Bacteria in Acne Development
- C. acnes can trigger host responses that have beneficial or detrimental consequences for the host, including colonization resistance, immune system interactions, and oxidant protection 4
- Dysbiosis, or an imbalance in skin microbiome homeostasis, may play a role in acne pathogenesis 2
- The skin microbiome in the follicle is composed of a diverse group of microorganisms, including C. acnes and Malassezia spp., which contribute to acne development 5