Scientific writing: Prebiotics to preserve the skin microbiota balance

Federico Benetti – Executive Director at ECSIN LAB, a Mérieux NutriSciences Company – has been involved in the publication of a scientific paper entitled “Effects of short chain fructo‑oligosaccharides on selected skin bacteria” on Nature.com/articles (2022).

Do you know how important is the skin care routine with biome-friendly cosmetic products?

Healthy skin is essential for preserving its physiology. The skin has its own unique ecosystem of bacteria, fungi and viruses, which play a key role and impact on both its functioning and its protection from external infections or toxic substances, and ensuring their balance is fundamental.
The skin care daily routine can affect this equilibrium if the cosmetic product is not designed to be biome-friendly to the point of disrupting the balance of microbiota and cause the skin condition dysbiosis. Described as an imbalance between the microbiota and its host, dysbiosis can be considered a form of impaired homeostasis in which the microbiota is shifted towards a less complex, less varied pathological spectrum.
While skin microbiota research is in an early stage, evidence suggests that there are many ways to be proactive about skin health, and more particularly about skin microbiota. A market research points out that an increasing number of skin care products started to incorporate prebiotics. The concept of prebiotics is well known for food product, in which they are used to promote the growth of beneficial bacteria of the gut microbiota – inducing subsequent health benefits -, and they could be applied to balance almost any microbial community, even the skin ones!

The aim of the study

The aim of the study was to evaluate the effects of short chain fructo-oligosaccharides (scFOS) from sugar beet (DP 3–5), well-recognised prebiotics, on the in vitro growth and competitive activity of bacterial strains representative of the human skin microbiota (as Staphyloccocus epidermidis, Cutibacterium acnes and Staphylococcus aureus).

The main points analyzed:

• Bacteriostatic and bactericidal activity of scFOS. The ability of scFOS to inhibit bacterial strains growth (i.e. bacteriostatic activity) and/or to exert bactericidal activity was evaluated by measuring the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC).
• Impact of scFOS on bacterial growth kinetics. The ability of tested strains to metabolize scFOS to sustain their growth.
• Competition between bacteria strains for scFOS. Bacterial ability to compete for scFOS as an energy source was evaluated by comparing S. epidermidis vs C. acnes and S. epidermidis vs S. aureus, at increasing scFOS concentrations.
• Bacterial strains competition for scFOS in RHE. The impact of scFOS on bacterial growth was evaluated on a reconstructed human epidermis (RHE) in vitro model characterized by a stratified epithelium and endowed with morphofunctional feature similar to the human epidermis.

Results

This study is the first to indicate that scFOS can effectively modulate the composition of the skin microbiota by inhibiting the growth of potentially pathogenic bacteria and, at the same time, promoting the growth of beneficial bacteria. scFOS can be considered an efficient ingredient to preserve or restore the natural individual balance of the skin microbiota and it can be used easily in skincare applications.