Probiotics and prebiotics in special kinds of yoghurts have long been shown to have beneficial effects on health. The cosmetics industry has jumped on the bandwagon, launching nutricosmetics and various cosmetic lines with probiotics to improve the appearance of the skin. Are they effective? Is there a future for these products?
Probiotics are beneficial microorganisms for our body that are incorporated in certain foods. Most are similar to microbiota (or flora), the bacteria that naturally occur in the intestine. Prebiotics, meanwhile, are substances that nourish these beneficial probiotics and help them grow.
Many scientific papers, published in journals like Current Opinion in Pharmacology, attest to the positive effects of probiotics and prebiotics on various diseases, including infectious diarrhoea and irritable colon disease. There is also scientific evidence in support of the influence of gut microbiota on obesity and allergic inflammatory processes. Consequently, science believes that managing gut flora via probiotic- and prebiotic-based diets could contribute to solving metabolic disorders.
What are the effects on our skin?
Can the gut flora have an impact on our skin? Is it possible to see the benefits of an ingested probiotic in the skin? This is, in fact, reported by a study published in the British Journal of Dermatology. The authors argue that taking a supplement of the probiotic Lactobacillus johnsonii (a bacterium that lives in the gut) in combination with carotenoids helps the immune system protect the skin from harmful ultraviolet rays. This would mean that prolonged combined use of these two elements would prevent the ageing effect of long-term sun exposure.
Probiotics: eat them or apply them to the skin?
Our skin provides a habitat for a wide range of microorganisms, most of them harmless. But acne and atopic dermatitis are caused by imbalances between these bacteria. Consequently, returning the natural balance to the skin flora using cosmetics containing probiotics and prebiotics would be an effective alternative to commonly used antibacterial products which do not restore the balance between microorganisms (they simply eliminate them).
For example, to rebalance the skin flora, a probiotic culture of microorganisms depleted by the imbalance could be applied to the skin, together with substances (prebiotics) to feed them.
Several examples illustrate the success of this new cosmetic principle. Tests have been performed to treat and prevent acne using probiotics that cull the population of Propionibacterium acnes (the bacteria associated with acne), in some cases with 91% effectiveness. And there are promising possibilities for the treatment of atopic dermatitis using Lactobacillus paracasei to improve the barrier function of skin and stimulate its immune system.
But not everyone in the scientific community views matters in the same light. For example, a review of 12 studies conducted on a total of 781 participants, published in Clinical & Experimental Allergy, questions the effectiveness of probioticos ingested for the treatment of atopic dermatitis (eczema). And it is not the only such study.
What is industry doing?
On the market in Japan since 1935 is the successful product Yakult, a yoghurt-and-probiotic-based drink, which, its manufacturers say, has many health benefits, including for the skin. Currently being investigated are new probiotics (strains of bacteria) aimed at developing topical cosmetics and new nutricosmetics along the lines of “beauty from within”.
In 2007 the French industrial giant Danone, meanwhile, launched Essensis yogurt, containing probiotic bacteria, vitamin E, antioxidants extracted from green tea and borage oil. Advertisements claimed that eating one daily significantly improved the appearance of the skin. Two years later this dermonutritional product was withdrawn, with Danone blaming weak sales.
And technology advance
Market studies indicate that cosmetics based on probiotics and prebiotics have an assured future. Many companies are conducting research along these lines and technical developments are regularly reported. Of the cosmetics firms using probiotic technology, the most advanced one includes a mixture of proteins derived from cryopreserved bacteria in its products. These are no longer living organisms and so do not need to be stored in the refrigerator.