Scientists from UPF and S-Biomedic have studied the use of living bacteria to modulate the microbial composition of the skin. In the work, published in the Microbiome magazine , they have used mixtures of different microbial components of the skin to temporarily modulate the composition of skin bacteria of recipients for therapeutic or cosmetic purposes.

The human body is host of a complex and rich microbial community, which mainly resides in the skin, the oral mucosa and gastrointestinal tracts, and has fundamental functions in the health and the disease. More specifically, the skin is colonized by a large number of microorganisms with a stable species composition over time. However, skin diseases, such as vulgar acne, eczema, psoriasis or dandruff, are associated with significant and specific microbial disorders.

Managed manipulation of human microbioma can be a potential therapeutic strategy for the treatment and study of diseases. The most prominent example is the treatment of antibiotic resistant bacteria Clostridium difficile in the intestinal microbial through fecal transplantation. In a similar way, the manipulation of the skin microbiome implies the promise of new therapeutic strategies for skin diseases.

The manipulation of the skin microbiome implies the promise of new therapeutic strategies for skin diseases.

“We are particularly interested in Cutibacterium Acnes and its diversity of strains, as this bacterium represents an important part of the microbial of human skin, and certain strains are associated with an imbalance in the microbiome that probably causes common acne,” explains Marc Güell , head of the Translational Synthetic Biology group of  the Department of Experimental and Health Sciences ( DCEXS ). “Therefore, we have developed and tested an approach to modulate the subpopulation of this species,” adds Güell.

For the study, the researchers prepared probiotic solutions from donor microbiomas and applied them to 18 healthy volunteers aged 22-42. Eight different areas of the skin were defined for application, in the chest and in the back, chosen because of their large abundance of sebaceous glands.

After a few weeks, the skin microbioma returns to the initial state and did not detect adverse effects.

They show that after the periodic applications of a donor microbiome, the receptor microbiome becomes more similar to the donor. The level of success depends on the composition of both microbiomas and the bacterial load applied.

“We see better results when using a multi-strain donor solution with a receptive skin rich in a specific subtype of Cutibacterium acnes with positive positive characteristics isolated from healthy individuals,” says Bernhard Paetzold , first author of the study and co-founder. Scientific director of S-biomedic. They saw that after a few weeks, the skin microbioma returned to the initial state and did not detect adverse effects.

This method opens up the possibility of developing probiotic solutions that help human skin to move from microbial states of disease to healthy ones. “We hope that this methodology can be used to study and modify the microbial components of the skin and can be applied in future therapies and searches in the skin microbiome and related diseases,” concludes Marc Guell.

The study involved researchers from the Center for Genomic Regulation ( CRG ), the University of Aarhus(Denmark) and the Otto-von-Guericke-Universität Magdeburg (Germany).