What is skin microbiota?
The skin microbiota is an ecosystem inhabited by a community of more than a million microorganisms (bacteria, viruses, fungi) per square centimeter of skin.
Bacterial composition of skin (cutaneous microbiota) is mostly dominated by the following genera: Propionibacteria (23%), Corynebacteria (22.8%) and staphylococci (16.8%).
Most of the bacteria in epidermis are “commensal” and live in a symbiotic manner with the host that they colonize.
Interactions between the host immune system and its microbiota contribute to the control of the skin bacterial composition as well as to the education of the adaptive immune system of the host.
Imbalance in the microbiota composition can cause cutaneous disorders (dry skin, oily skin, dandruff, etc.) and even pathologies (psoriasis, atopic dermatitis, acne, etc.).
The skin microbiota: models and in vitro assays
Thanks to its expertise in cellular and tissue engineering, Bioalternatives has developed in vitro or ex vivo study models that are suitable for analyzing the interactions between microbiota and skin:
- Isolated bacterial culture (Staphylococcus aureus, Staphylococcus epidermidis, Cutibacterium acnes, Corynebacterium xerosis …)
- bacteria on 2D skin models (keratinocytes, fibroblasts, sebocytes, etc.)
- bacteria on 3D skin models (reconstructed epidermis, etc.)
- infection experiments with the HSV-1 virus ( Herpes simplex virus type I)
Both the impact of compounds or formulations on the development of bacteria and the influence of bacteria on cutaneous response can be assessed by these models.
Bioalternatives offers a panel of solutions for the evaluation of:
- Bacterial viability
- Quantification of bacterial colony (CFU)
- Determination of bacterial load (qPCR (Taqman))
- Bacterial adhesion on 3D models (reconstucted epidermis) – quantification of colony, qPCR, radioactivity, SEM
- Biological response of 2D or 3D models (differentiation, inflammation and immune response)
Bioalternatives offers a wide range of microorganisms tested by our laboratory and available for in vitro testing:
GRAM (+) :
- Staphylococcus aureus
- Staphylococcus epidermidis
- Cutibacterium acnes
- Corynebacterium xerosis
- Streptococcus pyogenes
- Mix of several strains (upon request)
- Other strains upon request
GRAM (-) :
- Pseudomonas aeruginosa
- Other strains upon request
- Herpes simplex virus type 1 (HSV-1)
- Human Rhinovirus 16 (HRV-16)
Here are a few examples among all standard assays proposed by Bioalternatives in the field of skin microbiota:
Skin microbiota analysis
Our company has developed ready-to-use non-invasive collection kits to analyze the lipids and biomarkers of the skin surface from your samples or from those of your clinical center.
The qualitative and quantitative analysis of the bacteria present on the surface of the skin are carried out on samples with the SW Kit. They are performed using the following techniques:
- Traditional microbiology on agar
- Targeted qPCR
- Non-targeted metagenomic analysis
In addition, the analysis of sebaceous lipids (triglycerides and fatty acids) gives information on the lipase activities of bacteria and yeasts such as C. acnes and M. furfur, involved in the development of acne and dandruff respectively.
These evaluations help support your claims about the efficacy of “friendly” microbiota products, bacteriostats, antimicrobials, prebiotics, anti-acne products, anti-dandruff products, etc.