First-time use of a droplet-based microfluidic method to highlight specificities of microbiote communities from sensitive skin
Podium 21
Presented by: Sabrina Leoty-okombi
Up to 70% of women and 60% of men report having sensitive skin (Farage, 2019). Sensitive syndrome (SS) is a complex clinical phenomenon defined by the self-reported presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus, even though objectively measurable signs of irritation are not always present.
Although the skin microbiome is considered important in skin health, the relationship between the skin microbiome and skin sensitivity has received little attention. A first comparison was performed on several body zones of 3 men and 3 women (20-35yo) suffering from SS or not (NS). In this limited cohorta decreased percentage of Staphylococci and absence of Acinetobacter or Proteus were shown after culture of skin bacteria under aerobic conditions. However,there was no clear skin microbiome signature of the sensitive skin phenotype (Hillion et al. 2013). A later study on 42 Korean women (22-52yo, cheek) showed equivalent diversity of skin bacteria in SS, but a significant increase of Lactobacillus and Mucor racemosus and a decrease in Malassezia restricta (Keum et al. 2020). Finally, a larger study on caucasian women (SS 20-50yo and NS 23-50yo, cheeks) likewise did not show differences in diversity. However, a signature of discriminant genera was proposed with significant decreases in Cutibacterium, Lawsonella, Bacillus in SS (tendency for Staphylococcus), and increases in Corynebacerium, Snodgrassela, Kocuria, Micrococcus, Lactobacillus and Lactococcus (tendency for Chryseobacterium and Roseomonas) (Jarrin 2020).
In this study, we compare the composition then isolate in culture the skin microbiota of individuals with sensitive and non-sensitive skin. We recruited 40 panelists with normal skin with the largest possible diversity and 33 panelists declaring sensitive skin and tested for their hypersensitivity to heat. To characterize the composition of the skin microbiota, we sequenced the entire 16S rRNA gene using the PacBio technology to obtain unprecedented taxonomic resolution of the microorganisms present. We used droplet-based microfluidic technology (DBMT) for the first time to create a collection of specific bacterial strains isolated from individuals with sensitive and non-sensitive skin. The growth of representative strains was tested with 4 different concentrations of active ingredients to identify those ingredients with the potential to rebalance sensitive skin microbiota.
We compared the two cohorts to examine the presence of common or specific strains and to determine variations in abundance. Compared to existing literature, we confirmed the results for 5 bacterial genera of the 14 highlighted by previous authors such as the slight increases of abundance of Corynebacterium, Kocuria, Micrococcus and Lactococcus or the decrease of Staphylococci in the subjects reporting sensitive skin. However, in our conditions, some differences were observed: Snodgrassella was not detected in either cohort; Lawsonella was slightly increased in SS; or Chryseobacterium decreased in SS (as observed by Filaire 2019 in reactive skin). Interestingly, although Staphylococcus genus was decreased in overall abundance in SS, S. aureus had similar prevalence in both cohorts but slightly higher abundance in SS. Moreover, among the Corynebacterium species observed (22), C. kroppenstedtii had the most pronounced increase in abundance in SS, whereas several others were decreased. We also observed an increase of some Pseudomonas and a decrease in Lactobacilli.
Using DBM, we isolated several hundreds of strains to build our bacterial collection and selected those representatives of sensitive and non-sensitive skin conditions (~50), with several ribotypes for some bacteria. 5 active ingredients are currently under testing on these strains to evaluate which one, or which association, would provide the best performance to help to recover a microbial profile closer to the normal skin.
Our preliminary analysis showed interesting changes in the microbiome of individuals with sensitive skin. DBMT allowed the successful isolation in culture of the bacterial strains to build up our sensitive microbial library, including some strains recognized as difficult to culture. A better understanding of shifts in microbial communities in individuals with sensitive skin associated with the selection of ingredients on a clinical representative microbial collection is of real interest to select effective microbial rebalancing and skin soothing solutions for those specific consumers.
Although the skin microbiome is considered important in skin health, the relationship between the skin microbiome and skin sensitivity has received little attention. A first comparison was performed on several body zones of 3 men and 3 women (20-35yo) suffering from SS or not (NS). In this limited cohorta decreased percentage of Staphylococci and absence of Acinetobacter or Proteus were shown after culture of skin bacteria under aerobic conditions. However,there was no clear skin microbiome signature of the sensitive skin phenotype (Hillion et al. 2013). A later study on 42 Korean women (22-52yo, cheek) showed equivalent diversity of skin bacteria in SS, but a significant increase of Lactobacillus and Mucor racemosus and a decrease in Malassezia restricta (Keum et al. 2020). Finally, a larger study on caucasian women (SS 20-50yo and NS 23-50yo, cheeks) likewise did not show differences in diversity. However, a signature of discriminant genera was proposed with significant decreases in Cutibacterium, Lawsonella, Bacillus in SS (tendency for Staphylococcus), and increases in Corynebacerium, Snodgrassela, Kocuria, Micrococcus, Lactobacillus and Lactococcus (tendency for Chryseobacterium and Roseomonas) (Jarrin 2020).
In this study, we compare the composition then isolate in culture the skin microbiota of individuals with sensitive and non-sensitive skin. We recruited 40 panelists with normal skin with the largest possible diversity and 33 panelists declaring sensitive skin and tested for their hypersensitivity to heat. To characterize the composition of the skin microbiota, we sequenced the entire 16S rRNA gene using the PacBio technology to obtain unprecedented taxonomic resolution of the microorganisms present. We used droplet-based microfluidic technology (DBMT) for the first time to create a collection of specific bacterial strains isolated from individuals with sensitive and non-sensitive skin. The growth of representative strains was tested with 4 different concentrations of active ingredients to identify those ingredients with the potential to rebalance sensitive skin microbiota.
We compared the two cohorts to examine the presence of common or specific strains and to determine variations in abundance. Compared to existing literature, we confirmed the results for 5 bacterial genera of the 14 highlighted by previous authors such as the slight increases of abundance of Corynebacterium, Kocuria, Micrococcus and Lactococcus or the decrease of Staphylococci in the subjects reporting sensitive skin. However, in our conditions, some differences were observed: Snodgrassella was not detected in either cohort; Lawsonella was slightly increased in SS; or Chryseobacterium decreased in SS (as observed by Filaire 2019 in reactive skin). Interestingly, although Staphylococcus genus was decreased in overall abundance in SS, S. aureus had similar prevalence in both cohorts but slightly higher abundance in SS. Moreover, among the Corynebacterium species observed (22), C. kroppenstedtii had the most pronounced increase in abundance in SS, whereas several others were decreased. We also observed an increase of some Pseudomonas and a decrease in Lactobacilli.
Using DBM, we isolated several hundreds of strains to build our bacterial collection and selected those representatives of sensitive and non-sensitive skin conditions (~50), with several ribotypes for some bacteria. 5 active ingredients are currently under testing on these strains to evaluate which one, or which association, would provide the best performance to help to recover a microbial profile closer to the normal skin.
Our preliminary analysis showed interesting changes in the microbiome of individuals with sensitive skin. DBMT allowed the successful isolation in culture of the bacterial strains to build up our sensitive microbial library, including some strains recognized as difficult to culture. A better understanding of shifts in microbial communities in individuals with sensitive skin associated with the selection of ingredients on a clinical representative microbial collection is of real interest to select effective microbial rebalancing and skin soothing solutions for those specific consumers.