Prebiotic and Probiotic Skincare: Trend or Scientifically Proven?

The Skin Microbiome: A Complex Ecosystem

The skin is the largest organ of the human body and simultaneously a complex ecosystem colonized by a variety of microorganisms, known as the skin microbiome. This consists of bacteria, fungi, and other microbes that interact with each other and with the skin. Changes in the skin microbiome are being investigated in relation to various skin conditions. Against this background, prebiotic, probiotic, and fermented ingredients in skincare are increasingly coming into focus for research.

Prebiotic Skincare: Nutrients for Good Skin Bacteria

Prebiotic skincare products contain indigestible sugars, dietary fibers, or plant extracts that promote the growth and activity of beneficial microorganisms on the skin without harming the protective microbes. Typical prebiotic substances include inulin, oligofructose, or certain plant polysaccharides. They serve as a substrate for specific microorganisms and are therefore used particularly in connection with the skin microbiome and skin barrier.

Probiotic Skincare: Live and Dead Microbes

Various formulations are marketed under the term probiotic skincare. Some contain live microorganisms, others fermented extracts, lysates, or components of inactivated microorganisms. These differ significantly in composition and properties. Therefore, whether and what effects a specific formulation has on the skin microbiome or skin barrier must be investigated for the respective ingredient and product.

Mechanisms of Action of Pre- and Probiotic Skincare

Prebiotic, fermented, and microbial ingredients are investigated for various mechanisms in the skin microbiome. These include potential changes in microbial composition, as well as parameters of the skin barrier and skin hydration. However, the effects that actually occur depend heavily on the ingredient used, its concentration, and the specific formulation. Therefore, results for individual ingredients cannot be universally applied to all skincare products advertised as prebiotic or probiotic.

Application and Practical Tips

The use of pre- and probiotic skincare products should be tailored to the individual needs of the skin. For sensitive skin, a gentle introduction is recommended to avoid irritation. Mild formulations without strongly irritating ingredients can be a good choice, especially for sensitive skin, and can be gently integrated into the daily care routine. For skincare products, the visible effect depends on the formulation, ingredients, skin type, and regular application. Prebiotic or microbial ingredients alone do not allow for a general statement about how long it takes for changes to appear.

What to Look for in Pre- and Probiotic Skincare

When choosing pre- and probiotic skincare products, it is crucial to pay attention to the ingredients, quality, and formulation. Suitable products contain genuine prebiotic substances such as inulin, oligofructose, or fermented plant extracts. Probiotic formulations may contain live microorganisms or their fermented/dead cellular components. It is important to know that not all creams advertised as "probiotic" actually contain active microbes; often, they are just extracts that can nevertheless produce investigated effects. Depending on the skin type, strong degreasing surfactants, high alcohol concentrations, or other potentially irritating ingredients can affect skin tolerance. Therefore, the overall formulation of the respective product is crucial. For sensitive or acne-prone skin, it is advisable to introduce the products gradually at first to avoid possible irritation.

Storage also plays a decisive role in effectiveness. Pre- and probiotic products should be stored in a cool, dry place away from light. Some probiotic creams or serums require refrigeration to stabilize the microorganisms. In general, the effectiveness of live microbes can be impaired by heat, direct sunlight, or frequent opening of the packaging. The shelf life varies depending on the formulation but is usually between six and twelve months after the manufacturing date. Many products indicate a best-before date on the packaging and also include information on the recommended period of use after opening ("Period After Opening," PAO).

For skincare, regular use according to product instructions is advisable. Whether and how a formulation influences the skin microbiome depends on the specific ingredients it contains and their stability. Storage, packaging, and individual skin tolerance also play a role.

Here's the most important information at a glance:

Mechanisms of Action and Effects

Prebiotic, microbial, and fermented ingredients are being investigated in skincare for various potential mechanisms. These include changes in microbial composition, as well as parameters of the skin barrier and skin hydration.

The changes that actually occur depend on the specific ingredient used, its concentration, stability, and the overall formulation of the respective product. Therefore, results for individual ingredients cannot be universally applied to all skincare products marketed as prebiotic or probiotic, or to certain skin conditions.

Investigated Aspects of Pre- and Probiotic Skincare

• Support for a balanced skin microbiome
• Influence of certain formulations on skin barrier parameters
  
• Changes in the skin microbiome depending on the ingredient and formulation
  
• Potential improvement of skin hydration and protection against environmental influences
• Research on different skin conditions without a general efficacy claim for individual products
  

Practical Tips for Application

When selecting and using pre- and probiotic skincare products, the following aspects should be considered:

1. Ingredients:

• Genuine prebiotic substances (inulin, oligofructose, plant extracts) or fermented/probiotic extracts.
• Caution with products that use "probiotic" merely as a marketing term.
  

2. Skin type:

• For sensitive skin, it is particularly worthwhile to look for mild formulations and individual tolerance.
  
• For skin with acne or eczema, introduction should be gradual to avoid irritation.
  

3. Formulation:

• For sensitive skin, it is worth looking for mild formulations and individual tolerance. The overall composition of the respective product is crucial.
  

4. Regular application:

• Whether and when changes appear depends on the formulation, ingredients, skin type, and regular application. Therefore, a general timeframe cannot be given.

Trend or Scientifically Proven?

The skin microbiome is an active field of research in dermatology. Among other things, how certain prebiotic, microbial, and fermented ingredients relate to microbial composition, skin barrier, and skin hydration is being investigated. Nevertheless, the scientific evidence is not yet as extensive as in gut microbiome research, so not all marketing promises of the industry are demonstrably proven. Such products can be integrated into a skincare routine with mild cleansing, suitable moisturizing, and individually well-tolerated products.

Pre- and probiotic skincare is the subject of current microbiological and dermatological research. Different findings are available for various ingredients and formulations, which cannot be universally applied to all products or skin conditions. Therefore, the specific composition of the product, its tolerability, and the evidence for the ingredients used are crucial.

Do you want to make your own pre-/probiotic skincare? Here's a DIY guide with Kombucha:

Kombucha is a food product and not a tested cosmetic product. A homemade application on the skin is not standardized; pH value, hygiene, microbiological stability, and individual tolerance can vary. Therefore, anyone using kombucha for a DIY skincare routine should pay particular attention to clean preparation, appropriate dilution, and individual skin tolerance.

First, Kombucha tea is slightly diluted to bring its acidic pH of about 2.5–3.5 to skin-compatible values (approx. pH 4–5). Distilled water or aloe vera gel can be used for this. A mixing ratio of about 50% kombucha to 50% water or aloe vera gel has proven effective in practice. This mixture can be used as a simple DIY toner serum. Due to its acidic pH, it should first be carefully tested on a small skin area.

Preparation should be done under hygienic conditions, as uncontrolled fermentation increases the risk of unwanted microorganisms. Clean utensils, sealed glass containers, and refrigeration are essential. The finished DIY product should be used within 5–7 days to ensure freshness and safety. Before widespread application, a patch test is recommended to rule out any skin reactions.

For application, the kombucha serum is applied to cleansed skin and gently patted in. In a DIY application, fermented components come directly into contact with the skin. Therefore, hygienic preparation, appropriate dilution, and individual tolerability are particularly important. This care can be used daily or several times a week, depending on skin type and tolerability.