Microbiome Modulation in Acne Patients and Clinical Correlations

Area of Science:

• Dermatology
• Microbiome research
• Medical research

Background:

• Acne vulgaris is linked to an imbalanced skin microbiota, with specific Cutibacterium acnes (C. acnes) ribotypes exacerbating inflammation.
• C. acnes ribotypes RT4 and RT5 are associated with increased biofilm formation and inflammatory acne lesions.
• C. acnes RT6 represents a non-acne strain beneficial for skin health.

Purpose of the Study:

• To evaluate the clinical efficacy of a novel topical emulsion in treating acne vulgaris.
• To investigate the impact of the emulsion on the skin's microbial composition using metagenomic analysis.

Main Methods:

• An open clinical trial involving 32 adult acne patients with Investigator Global Assessment (IGA) scores >1<3.
• Patients applied a topical emulsion containing Umbelliferae vegetal extract and polysaccharide (1%) twice daily for 2 months.
• Skin swabs from lesional and non-lesional sites were collected at baseline and 2 months for metagenomic long-read 16S rDNA sequencing.

Main Results:

• Significant clinical improvement observed, with mean IGA scores decreasing from 3.1 at baseline to 1.5 at 2 months (p < 0.001), a 63% reduction in lesions.
• Metagenomic analysis revealed a shift in C. acnes populations: increased abundance of RT6 (non-acne strain) and decreased abundance of RT1-RT5 (acne strains) (p < 0.0001).
• Staphylococcus epidermidis (S. epidermidis) ribotypes showed a non-significant increase.

Conclusions:

• The topical emulsion demonstrated significant efficacy in improving acne severity, as evidenced by clinical assessments.
• Treatment correlated with a favorable shift in skin microbiome composition, characterized by an increased abundance of beneficial C. acnes RT6.
• The findings suggest a microbiome-modulating mechanism underlying the emulsion's therapeutic effect in acne treatment.