Everything you need to know about probiotics.

Different from prebiotics and postbiotics, probiotics are microorganisms (bacteria, viruses, yeasts...) that are external to the body. According to the definition given by the World Health Organisation (WHO) and the Food and Agriculture Organization of the United Nations (FAO), probiotics are "live microorganisms which, when consumed in adequate amounts, have a health benefit on the host". They are particularly used to reduce blood pressure, combat tumours and diseases of the central nervous system, and treat certain intestinal diseases.

Presented as dietary supplements or incorporated into cosmetic products, probiotics join the intestinal or skin microbiota to balance and strengthen the populations of microorganisms that live there. Probiotics have a wide range of applications and are present in various fields: therapeutic, food, cosmetic... Due to their numerous benefits, it is estimated that the global probiotics industry is growing at a rate of 15 to 20% per year.

The strains of microorganisms selected to produce the probiotics used in cosmetics or in the food industry are carefully chosen. They are then cultivated in a suitable nutrient medium, often based on water, nitrogen, carbohydrates, salts and micronutrients. They then multiply in a controlled manner before being subjected to successive fermentations interspersed with centrifugation stages, which are essential for concentrating the microorganisms.

The stabilisation of these and the cessation of ongoing chemical reactions are then achieved by freezing and/or freeze-drying. After which, the freeze-dried materials are ground into a fine powder that can be mixed with excipients and other functional ingredients: this is the powder probiotic, which can then be incorporated into capsules or creams.

If probiotics are increasingly favoured in the cosmetic market, it's because they possess interesting properties in skin and hair applications.

• Probiotics aid in hydrating the skin and the scalp.

  When applied topically, probiotics can contribute to maintaining hydration in the cells of the skin and scalp. Studies in vitro have indeed found that the strain of bacteria Lactobacillus plantarum could increase the content of hyaluronic acid, an active ingredient with a strong affinity for water and capable of retaining up to 1000 times its weight in water. By thus enhancing the hydration of the skin and scalp, probiotics help to protect them and combat feelings of tightness.

• Probiotics prevent skin sagging.

  Furthermore, probiotics are often used in cosmetic treatments aimed at preventing the first signs of wrinkles. Depending on the strains of microorganisms, the mechanisms involved vary slightly. Some probiotics inhibit elastase, an enzyme that breaks down elastin, while others promote the production of filaggrin, a protein constituent of the stratum corneum. These actions help to maintain supple and firm skin.

• Probiotics combat oxidative stress.

  Various studies have highlighted the antioxidant properties of certain probiotics. Those derived from Lactobacillus have been particularly studied and have demonstrated their ability to stimulate the activity of antioxidant enzymes present in the body, resulting in a decrease in the rate of free radicals. Probiotics can therefore be used to protect cellular constituents from oxidative stress.

• Probiotics possess anti-inflammatory properties.

  Itching, redness, irritation... These are the signs characterising an inflammatory reaction. Certain probiotics have shown in studies an interesting soothing potential to alleviate these symptoms. Most often, it was the strain Lactobacillus, but the bacteria Bifidobacterium and Streptococcus also have potential benefits and can control the release of pro- and anti-inflammatory cytokines.

• Probiotics to reduce pigmentation spots?

  In vitro research has shown that certain probiotics such as Bifidobacterium and Lactobacillus can interfere with the expression of tyrosinase, a key enzyme in melanogenesis. These studies thus provide hope for a potential use of probiotics as an anti-brown spot agent. However, clinical trials are still necessary before a definitive conclusion can be reached.

Given that probiotics are microorganisms, it is natural to question whether their application could disrupt the skin flora and lead to adverse effects such as redness, irritation or blemishes. However, to date, scientific literature reports an absence of side effects following the topical use of probiotics. Moreover, the microorganisms incorporated into cosmetic formulations are often not "alive" but "dormant", thus unable to grow. This does not mean they are useless for our skin as the molecules they contain, particularly in their vesicles, remain active and are a source of skin benefits.

Please note : We are discussing here only about thetopical application of probiotics. The oral intake of dietary supplements based on these microorganisms is different and requires more precautions, and ideally a medical opinion.

At Typology, you can find the probiotic ferment Lactobacillus in our exfoliating night cream. The keratolytic action of this microorganism complements that of glycolic and mandelic acids, exfoliating actives. Known for their astringent and deep-cleansing virtues, AHAs help to reduce the presence of blackheads and tighten dilated skin pores. By acting during the night, our cream helps to remove the superficial layers of the epidermis to renew the skin and achieve a smoother and brighter complexion.

Due to its high concentration of AHA, it is important to note that this night cream is not recommended for sensitive skin and the application of a sunscreen in the following days is essential. Furthermore, it contains true lavender essential oil, an oil with purifying and regenerating properties which, like all essential oils, is not recommended for pregnant or breastfeeding women.

• OUWEHAND A. & al. The Production and Delivery of Probiotics: A Review of a Practical Approach. Microorganisms (2019).

• YU J. & al. The use and process of probiotics in skincare: A review. Journal of Cosmetic Dermatology (2022).

• QI H. Application of Probiotics and Metazoans in Cosmetics. The 2nd International Conference on Biological Engineering and Medical Science (2023).

• XU Z. & al. Applications of Probiotic Components in Cosmetics. Molecules (2023).