A multi-strain human skin microbiome model provides a testbed for disease modeling

Area of Science:

• Microbiology
• Dermatology
• Tissue Engineering

Background:

• The skin microbiome is crucial for skin health, influencing immunity and barrier function.
• Dysbiosis is linked to inflammatory skin diseases like atopic dermatitis and psoriasis.
• Current in vitro models lack the complexity and duration to study chronic disease states.

Purpose of the Study:

• To develop a stable, complex in vitro model of the human skin microbiome.
• To characterize host-microbe interactions and disease impacts over time.
• To provide a testbed for evaluating commensal influences and environmental factors.

Main Methods:

• Co-culture of a six-strain microbial consortium with primary human keratinocyte-derived tissue.
• Utilized an Air-Liquid Interface culture system for up to 7 days.
• Assessed tissue health via histology, gene expression, transepithelial electrical resistance (TEER), and microbial strain abundance using qPCR.

Main Results:

• The model formed complex skin tissue and maintained stable TEER.
• Up to five microbial strains remained viable on the tissue surface for 7 days, including Cutibacterium acnes.
• Disease-associated cytokines reduced tissue barrier function, and disease states altered microbial composition.

Conclusions:

• This in vitro model offers a robust platform for studying skin microbiome dynamics and host interactions.
• The model supports the growth of native skin strains like C. acnes under more natural conditions.
• It can be used to investigate the impact of disease states on the microbiome and vice versa.