Microbial Reference Frames Reveal Distinct Shifts in the Skin Microbiota after Cleansing

Area of Science:

• Microbiology
• Dermatology
• Biochemistry

Background:

• Skin cleansing is essential for hygiene but can negatively impact the skin's natural barrier and microbiome.
• Understanding the effects of cleansing products on skin microbiota is crucial for developing effective skincare.

Purpose of the Study:

• To investigate the impact of a liquid body wash on the skin's microbial composition.
• To identify specific microbial shifts associated with skin cleansing and moisturizing ingredients.

Main Methods:

• A placebo-controlled clinical study involving 30 Caucasian women.
• Application of a liquid body wash on volar forearms twice daily for one week.
• Skin microbiome sampling via swabbing and 16S rRNA sequencing.

Main Results:

• Skin cleansing induced immediate shifts in microbial composition, observable within 1 hour.
• A dynamic microbial equilibrium was established by day 1 and maintained throughout the study.
• The active treatment enriched potentially beneficial *Paracoccus marcusii* and reduced potentially pathogenic *Brevibacterium casei* and *Rothia mucilaginosa*.

Conclusions:

• Skin cleansing significantly alters the cutaneous microbiome composition.
• Specific ingredients, like saccharide isomerate, can influence the skin's microbial profile.
• The study highlights the potential for skincare products to modulate the skin microbiome towards a healthier state.