Skin microbiota

From volunteer to microbiota: evaluation of the impact of products on skin bacterial flora

Ten times more numerous than human cells, the billions of bacteria present in our body constitute a real ecosystem called “microbiota”. If the intestinal microbiota is clearly characterized nowadays, the skin microbiota is barely known. Recent studies show that microbial colonization of the skin surface, hair follicles or glands may contribute, along with the immune system, to protect the skin from foreign aggression and to keep it “healthy”.

SMALTIS expertise makes it possible to explore skin flora in depth, and to support the development of products acting on this microbiota, in order to maintain or rebalance it. SMALTIS thus delivers a unique and tailor-made offer to study the microbiota of the skin, via in vivo, ex vivo and in vitro models.
With in vivo model, a complete service allows to test, on a cohort of volunteers, the clinical impact of active ingredients or finished cosmetic products, and their effects on the cutaneous bacterial flora.


DNA sampling and extraction: total flora sampling

For studies on healthy volunteers, SMALTIS can collaborate with the company Skinexigence specialized in the evaluation of efficacy of cosmetic products on healthy volunteers (panel of about 3500 people).
The proximity of our two companies and the complementarity of our skills make it possible to combine biometrological measurements (fringe projection, photography, thermography, videocapillaroscopy, laser doppler imaging, ultrasound...) and microbiota characterization.
Volunteers are recruited according to well-defined criteria (age, skin type, degree of hydration, etc.), then hosted by Skinexigence where the various biometrological tests and microflora samples are carried out. These are systematically carried out by the same microbiologist and processed in a very short period of time to ensure the reproducibility and reliability of the results.

For in vivo studies on volunteers suffering from skin diseases, the service is also possible, for example by sending DNA sampling kits to the company conducing the tests on these subjects.

Sequencing with qualified providers

Composition of bacterial flora of each sample is then determined by high throughput sequencing of the DNA encoding 16S ribosomal RNA. NGS (Next Generation Sequencing), metagenomics and metatranscriptomics are used. A statistical and microbiological analysis of data is then carried out to provide a comparative, quantitative and qualitative study of skin bacterial populations (diversity, relative abundance, etc.).

Post-metagenomic exploration

Well beyond the sequencing and quantitative/qualitative analysis of these bacterial populations, a real post-metagenomic exploration is carried out, SMALTIS striving to go as far as possible in the exploitation of the results. 
The SMALTIS microbiology team then seeks to explain data obtained, to establish correlations with literature data and observed clinical phenomena, to understand interactions between a compound and skin bacteria and their impact, to study specific biomarkers and properties, to anticipate the effects of a change in bacterial population on metabolite production... Other models can be used, such as in vitro and ex vivo models. A study of specific bacterial populations can be carried out, depending on the projects.

Thus, through a solid scientific basis, SMALTIS strives to establish a study model that will provide the most reliable results and a complete and relevant analysis of the effects of candidates on cutaneous microbiota.


EXPLAIN interactions between bacteria and skin
UNDERSTAND impact of products on the skin's flora
IDENTIFY specific properties & biomarkers


Correlation with literature and clinical parameters
Study of specific bacterial populations
Study of skin pathologies - Already studied: rosacea, vaginosis, acne