Dr. Anne Gürtler works at the Dermatology Clinic of Ludwig Maximilian University of Munich and is a member of the German and European Society for Nutritional Medicine. Since specializing as a nutritionist, she has been researching the connection between nutrition and inflammatory skin diseases. We asked her some exciting questions about the skin microbiome, as well as questions about the connection between the gut and the skin.
Our skin is the largest organ of the human body and hosts more than 10 billion bacterial cells, ranging from 10² to 10⁶ per square centimeter depending on the region. After the gut, human skin contains the second highest number and diversity of microorganisms. As the body's first line of defense, human skin forms a physical and chemical barrier against the intrusion of foreign substances or microorganisms and has an immune system that helps fight infections. This happens, among other things, through the symbiosis of bacteria. The connection between our gut and skin microbiome is so close that the skin can be called the "mirror of the gut"—it essentially shows how "healthy" we are inside.
We also asked Dr. Anne Gürtler about which skin diseases can be associated with a disturbed skin microbiome, what should be considered in skin care, and which foods are particularly beneficial for the skin.
Can you name 3 signs of the most common symptoms/indications that the skin microbiome is out of balance?
Dr. Gürtler: There is no clear single sign here. Rather, a disturbed skin microbiome can influence many skin diseases, which then manifest differently. Our skin is inhabited by countless microorganisms that usually live together peacefully. The totality of bacteria, viruses, fungi, and mites is called the microbiome. In some skin diseases, this balance can be disturbed, leading to inflammation and eczema flare-ups. For example, in acne, there is an increased presence of so-called Cutibacterium acnes, in rosacea more Demodex mites, and in atopic dermatitis Staphylococcus aureus compared to healthy skin.
What can be done about it?
Dr. Gürtler: Targeted therapy can be initiated, for example, through topical treatment with prescription creams. For this, a dermatologist should be consulted. In addition, daily lifestyle can be crucial. In skin care, "more is better" does not always apply. I often see that for skin impurities, an overly complex cleansing and care routine is performed. Returning to three products can help the skin regenerate and regain balance:
- Mild cleansing morning and evening (no harsh scrubs to prevent micro-injuries to the skin),
- Skin care (fragrance-free care following face washing),
- Sun protection (in the morning). Skin care should be individually tailored to the skin type. Consultation with a dermatologist and/or medical cosmetologist is also recommended.
What fascinates me personally is the connection between skin and nutrition. According to the latest findings, the organs skin and gut seem to be more closely connected than previously thought. In some skin patients, alongside a disturbed skin microbiome, there is also an altered composition of the gut microbiome, with some species increased and others decreased compared to healthy skin. Our daily diet is considered an important influencing factor for the gut microbiome. Clinical studies are currently investigating whether dietary modulation of the gut microbiome can bring about positive effects on the skin.
What can already be said: a varied diet characterized by seasonal, unprocessed, plant-based staple foods seems to promote (skin) health. Probiotics and prebiotics are particularly interesting.
Probiotics: live microorganisms that provide a health benefit to the body. These include, for example, lactic acid bacteria and bifidobacteria. These can be produced through fermentation of foods (sauerkraut, miso, kimchi, kombucha). They can also be taken as supplements. Previous studies with acne patients showed, for example, that taking probiotics over several weeks can improve the skin's appearance and positively change corresponding markers in blood and tissue.1
Prebiotics: food components that the body cannot break down but whose consumption promotes the growth and activity of gut organisms. These include, for example, starch in potatoes and whole grains and pectin in fruits and vegetables.
