In this study the topical use of cream with live probiotic bacteria was evaluated for its efficacy in reducing acne symptoms and its effect on the skin microbiota on patients with acne. Patients with mild to moderate acne used the probiotic cream for 8 weeks and clinical evaluation and sampling was done at start, 4, 8 and 10 weeks. Next-Generation Sequencing was used to analyze the skin microbiota of the patients.

Probiotics are live micro-organisms which when administered in adequate amounts can exert a health benefit on the host. This health-promoting effects have been extensively studied in the gastrointestinal niche but it becomes more and more clear that other niches are also interesting for the potential of probiotics. Recent breakthroughs in 'next generation sequencing' (NGS) technologies are making it now possible to map the microbiota after DNA extraction, which is very interesting for bacteria that are not or difficult to cultivate. The research into the microbiota of the skin with such new NGS technologies currently limited, but shows that there is also an equilibrium in the skin composition of the microbiota and that there is a disturbance of the skin microbiota in acne (Murillo & Raoult, 2013). In acne vulgaris it is known that the condition is multifactorial and that both hormonal triggers and environmental factors play a role. However, it is also known that Propionibacterium acnes play an important role in the inflammation of the sebaceous gland follicles. Probiotic strains with antipathogenic activity against this bacterium and suitable for application to the skin is thus potentially able to restore the balance of the skin microbiota and reduce acne symptoms.

Inclusion Criteria:

• mild to moderate acne

Exclusion Criteria:

• local treatments, including cleansers, soaps, antimycotics and antibiotics within 2 weeks prior to start of study
• use of oral antibiotics within 4 weeks prior to start of study
• use of systemic retinoids within 6 months prior to start of study