The cosmetic industry is especially interested in developing products that maintain and/or improve a healthy skin microbiota.
Therefore, Complife’s team together with other experts chose to investigate in detail the structure and composition of the basal bacterial community of the face.
The objective of this study was to pinpoint the pattern differences between the male and female facial microbiomes and our team decided to focus on the cheek.
From a pool of over 300 samples from both male and female volunteers, we matched one-to-one 96 samples from the cheek (48 women and 48 men) based on season and living area to limit the influence of these factors.
METHODS & INSTRUMENTS
- Raw sequences were processed by MicrobAT (Microbiota Analysis Tool) v. 1.1.0 software (SmartSeq Srl, Novara, Italy). For each sample, the software identifies the microbiota members at the Phylum, Class, Order, Family, Genus, and Species level. Moreover, from MicrobAT, three files were generated and processed by Microbiome Analyst software to analyze the bacterial community as a whole while filtering the lower quality data.
- The biodiversity within and between our groups was calculated using the phyloseq package.
- Alpha-diversity was assessed using the Shannon and the Simpson indexes.
- Beta-diversity was measured using Bray–Curtis dissimilarity, graphical representation of the matrices was obtained using Principal Coordinate Analysis (PCoA), and the statistical significance of the clustering model of the sorting graphs was assessed using permutational analysis of variance (PERMANOVA).
- Statistical differences in taxa abundance between the male and female groups were assessed by applying the Linear Discriminant Analysis (LDA) Effect Size (LefSe) method.
- Finally, two-way ANOVA was used to discriminate the effects of the two factors (“sex” and “age”) and of their interaction (“sex X age”).
Read the full study HERE
We successfully demonstrated that sex is a crucial factor in shaping the microbial community of the human face, and the identification of low-abundance, high-relevance entities suggests that factor-driven microbiota variations do not necessarily depend on the most abundant members of the microbial flora.
In future these differences observed between male and female subjects could become the cornerstone for developing more personalized skincare, and observation of other variables (age, hormone levels, etc.) will allow to gain a better understanding of the interdependent relationship between a given microbiota and its host.
Finally, the constant exposure of the face to the external environment should allow to study the influence of exogenous parameters such as seasonality or atmospheric pollutants.
| CLEMENCE ROBERTS – Research Scientist
| FEDERICA CASCELLA – PhD Student (doctoral scholarship co-financed by Complife)
| VINCENZO NOBILE – R&D Manager and Cosmetics Market manager
PLEASE FEEL FREE TO REACH US FOR FURTHER INFO ABOUT THIS STUDY OR ANY QUESTION ABOUT YOUR PROJECTS.
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