Beauty from within: understanding the gut-skin axis

The essentials at a glance

• The gut-skin axis describes a reciprocal communication between the gut microbiome and the skin via the immune system, inflammation, and metabolism.
• Review articles discuss a link between the composition of the gut microbiome and inflammatory skin conditions such as acne, rosacea, atopic dermatitis, and psoriasis.
• Fiber from plant-based foods is fermented by gut bacteria into short-chain fatty acids, which are involved in the regulation of inflammation.
• Fermented foods such as yogurt, kefir, or lacto-fermented vegetables can support diversity in the gut.
• At Tannerhof, the Aesthetics program combines Schlanke Tanne Low Carb with the gut-skin axis and regional natural cosmetics – medically supervised, without empty promises of beauty.

What the gut-skin axis means

Beauty from within is more than just a saying. Behind the concept lies a well-studied idea: the condition of the gut and the appearance of the skin are linked. In medical research, this connection has its own name: the gut-skin axis. It refers to a reciprocal communication between the gut, with its trillions of microorganisms, and the skin, the body's largest organ.

This communication does not happen directly, but through indirect pathways. A 2022 review article in the journal Gut Microbes describes how the gut microbiome influences the skin through the regulation of systemic immunity, inflammatory responses, and metabolic pathways. Simply put: what happens in the gut sends signals that reach the immune system throughout the body – and thus the skin as well. Tannerhof incorporates this connection into its Aesthetics health program, which links the gut-skin axis with nutrition and natural cosmetics.

It is important to keep things in perspective: the gut-skin axis is a field of research, not a switch you can simply flip. Much has been described, while some aspects are still under investigation. At the Naturhotel Tannerhof, this knowledge is therefore not presented as a promise, but as a medically supervised approach that starts with nutrition and complements it with external skincare.

How the gut and skin are connected

To turn this idea into a mechanism, it is worth looking at the bridge between the two organs. Three pathways are repeatedly mentioned in the literature: the immune system, inflammation regulation, and metabolism.

A frequently cited review article in Frontiers in Microbiology from 2018 places the gut microbiome at the center of this axis. The authors describe how gut bacteria produce metabolic products that help regulate the immune system. When the diversity in the gut becomes unbalanced – known in research as dysbiosis – the balance of messenger substances that dampen or trigger inflammation in the body also shifts. This very regulation of inflammation is the common denominator for many skin conditions.

The reciprocal nature of this relationship is key. It is not just the gut that speaks to the skin; the skin can also affect the gut. The image of an axis is therefore more accurate than that of a one-way street. In practice, this means that anyone wanting to support their skin from within should first look at their diet and how it affects the gut.

Which skin conditions are being discussed

Review articles consistently feature a recurring list of inflammatory skin diseases where a link to the gut microbiome is being investigated. The 2022 Gut Microbes paper mentions, among others:

• Acne (acne vulgaris),
• Rosacea,
• Atopic dermatitis (eczema),
• Psoriasis,
• as well as alopecia areata.

This does not mean that the gut is the sole cause of these conditions. It means that the composition of the gut microbiome is being discussed as one factor among many – and that nutrition therefore becomes a starting point that complements, rather than replaces, specialized dermatological treatment.

Nutrition as a lever: Fiber and fermented foods

If the gut is the bridge, then nutrition is the building material. Research highlights two key components in particular: fiber and fermented foods.

Fiber consists of indigestible plant fibers found in vegetables, legumes, nuts, and seeds. It reaches the large intestine undigested, where it serves as food for the bacteria residing there. During fermentation, this produces short-chain fatty acids, primarily butyrate, propionate, and acetate. A 2018 study in Frontiers in Microbiology describes these short-chain fatty acids as central regulators: they support regulatory immune cells and can dampen excessive inflammatory responses. The authors note that the low-fiber, high-fat Western diet reduces the formation of these protective metabolic products.

The second component is fermented foods. Yogurt, kefir, lacto-fermented vegetables, and other fermented dishes provide living cultures and substances created during the fermentation process. Review articles discuss their potential contribution to the diversity of the gut microbiome. Here, too, a sober assessment applies: there are indications and observations, but no automatic results. However, the common thread is a varied, plant-based, fiber-rich diet that includes fermented foods.

This is exactly the direction of the nutrition at Tannerhof, as detailed in the Healing Fasting and Schlanke Tanne hub. Even the post-fasting week structure is guided by the question of what benefits the microbiome: easily digestible vegetables, fermented foods, plenty of fiber, and mindful chewing.

Schlanke Tanne Low Carb and the skin

At Tannerhof, Schlanke Tanne Low Carb – our in-house low-carb diet – forms the nutritional foundation for the Aesthetics program. It is not based on restriction for its own sake, but on substance: low in carbohydrates, rich in vital nutrients, and featuring high-quality protein, plenty of vegetables, fiber, and healthy fats. The philosophy behind it is to prioritize the enjoyment of food and a zest for life over restriction.

Several components of this diet address the key levers of the gut-skin axis:

• Plenty of vegetables and salad provide fiber and phytonutrients – the fuel for a diverse gut microbiome.
• Healthy fats from olive, rapeseed, and linseed oil instead of trans fats from fried and processed foods.
• Fewer refined carbohydrates and fewer sweetened beverages, meaning less of what characterizes a pro-inflammatory diet.
• High-quality protein from fish, organic meat, quark, yogurt, cheese, mushrooms, or tofu for satiety and metabolism.

Schlanke Tanne is available at the hotel in two versions – Schlanke Tanne Drei with three meals a day, and Schlanke Tanne Intervall, which combines low carb with a 16-hour fasting window. For home, our Schlanke Tanne Zuhause approach describes how to incorporate this diet into everyday life, including one "cheat day" per week without any guilt. Which version is right for whom is discussed during the medical nutritional consultation at Tannerhof – the individual is the focus, not a rigid plan.

The Tannerhof approach: Aesthetics between gut and skin

The Aesthetics health program brings together the two sides featured in this story: the internal side of nutrition and the external side of skincare. The nutritional foundation is Schlanke Tanne Low Carb, with a thematic focus on the gut-skin axis. It is explicitly not a beauty promise or an aesthetic-surgical approach, but a medically supervised path that begins with nutrition.

From a medical perspective, the Tannerhof does not view the skin in isolation. Our physical examinations include bioimpedance analysis, which measures body composition in terms of water, muscle, and fat content. A wide range of therapies—including massages, wraps, baths, and breathing and movement exercises—is available to complement your stay, depending on your individual needs and medical consultation.

For external care, we rely on natural cosmetics, with a conscious focus on regional products. At the Tannerhof, we use only two labels: Pharmos Natur from Bernried and Marias from Salzburg. These lines provide the basis for our skin treatments, such as the Roseléne treatment with aloe vera lipids, which combines cleansing, intensive exfoliation, a customized special mask, a hand and arm massage, and a finishing treatment, or the Sesamé treatment with aloe vera and cold-pressed black sesame oil. You can find an overview of our entire range of treatments on the corresponding page of our website.

This creates an approach that connects two directions without prioritizing one over the other: nutrition, which begins in the gut and can influence the skin via this axis, and skincare, which nurtures the skin from the outside. The body is nourished from within—this long-standing Tannerhof philosophy takes on a very concrete meaning in light of the gut-skin axis.

Discover beauty from within at the Tannerhof

At the Tannerhof Nature Hotel, beauty from within is not just a promise, but a philosophy: starting with nutrition, taking the gut seriously as a key player, and supplementing with regional natural cosmetics. All this is nestled in Bayrischzell, between alpine meadows, mountain streams, and views of the Wendelstein—my mountain hideaway as the setting for a break where you can find peace. If you would like to take a closer look at our approach—combining our "Schlanke Tanne" low-carb concept, the gut-skin axis, and natural cosmetics—and book online, you can find it in our Aesthetics program.