Beauty from within: understanding the gut-skin axis

Key points

• The gut-skin axis describes a two-way communication between the gut microbiome and the skin, running through 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.
• Dietary fibre from plant foods is fermented by gut bacteria into short-chain fatty acids, which take part in regulating inflammation.
• Fermented foods such as yoghurt, kefir or lacto-fermented vegetables can support diversity in the gut.
• At the Tannerhof, the Aesthetics programme combines Schlanke Tanne Low Carb with the skin-gut axis and regional natural cosmetics – medically supervised, with no beauty promises.

What the gut-skin axis means

Beauty from within is more than a turn of phrase. Behind the image sits a well-studied idea: the state of the gut and the condition of the skin are connected. In medical research this link carries its own name, the gut-skin axis. It refers to a two-way communication between the gut, with its trillions of microorganisms, and the skin, the body's largest organ.

This communication is indirect. A review in the journal Gut Microbes from 2022 describes how the gut microbiome acts on the skin by regulating systemic immunity, through inflammatory responses and through metabolic pathways. Put simply: what happens in the gut sends signals that reach the immune system across the whole body, and with it the skin. The Tannerhof takes up this connection in its Aesthetics health programme, which combines the skin-gut axis with nutrition and natural cosmetics.

The framing matters. The gut-skin axis is a field of research, not a switch you flip. Much has been described, some is still under study. At the Naturhotel Tannerhof this knowledge is therefore not presented as a promise but as a medically supervised approach that begins with nutrition and complements the skin from its well-tended outer side.

How gut and skin are connected

To turn the idea into a mechanism, it helps to look at the bridge between the two organs. Three routes come up again and again in the literature: the immune system, the regulation of inflammation and metabolism.

A much-cited review in Frontiers in Microbiology from 2018 places the gut microbiome at the centre of this axis. The authors describe how gut bacteria produce metabolites that help steer the immune system. When diversity in the gut falls out of balance – dysbiosis, in research terms – the balance of the messengers that dampen or fuel inflammation in the body shifts as well. This regulation of inflammation is the common denominator of many skin conditions.

The two-way direction is part of it. It is not only the gut that speaks to the skin; the skin can also act back on the gut. The image of an axis is therefore more fitting than that of a one-way street. In practice this means: anyone who wants to support their skin from within looks first at nutrition and at what it does in the gut.

Which skin conditions are discussed

The review articles return to a recurring set of inflammatory skin conditions in which a link with the gut microbiome is examined. The 2022 Gut Microbes paper names, among others:

• Acne (acne vulgaris),
• Rosacea,
• Atopic dermatitis (neurodermatitis),
• Psoriasis,
• and alopecia areata (patchy hair loss).

This does not mean the gut causes these conditions on its own. It means the composition of the gut microbiome is discussed as one factor among several – and that nutrition thus becomes a starting point that does not replace specialist dermatological treatment but complements it.

Nutrition as the lever: fibre and fermented foods

If the gut is the bridge, nutrition is the building material. Two components stand out in the research: dietary fibre and fermented foods.

Dietary fibre consists of indigestible plant fibres from vegetables, pulses, nuts and seeds. It reaches the large intestine undigested, where it feeds the bacteria living there. Fermentation produces short-chain fatty acids, chiefly butyrate, propionate and acetate. The 2018 Frontiers in Microbiology paper 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-fibre, high-fat Western diet reduces the formation of these protective metabolites.

The second component is fermented foods. Yoghurt, kefir, lacto-fermented vegetables and other fermented dishes provide live cultures and substances formed during fermentation. Review articles discuss their possible contribution to the diversity of the gut microbiome. Here too the sober framing holds: indications and observations, not an automatic effect. What does emerge as a through-line is a varied, plant-forward, fibre-rich diet with a place for fermented foods.

This is exactly the direction the food at the Tannerhof points in, set out in the Heilfasten and Schlanke Tanne hub. Even the build-up after a fasting week follows the guiding question of what is good for the microbiome: easily digestible vegetables, fermented foods, plenty of fibre and mindful chewing.

Schlanke Tanne Low Carb and the skin

At the Tannerhof, Schlanke Tanne Low Carb, the house's own low-carb way of eating, forms the nutritional basis for the Aesthetics programme. It is not built on going without for its own sake but on substance: low in carbohydrates, rich in nutrients, with high-quality protein, plenty of vegetables, fibre and good fats. When the gain in pleasure and joy of life, rather than going without, takes centre stage – that is how the house describes the attitude behind it.

Several elements of this way of eating touch precisely on the levers of the gut-skin axis:

• Plenty of vegetables and salad provide fibre and phytonutrients – food for a diverse gut microbiome.
• Good fats from olive, rapeseed and linseed oil instead of trans fats from fried and processed food.
• Fewer fast carbohydrates and fewer sweetened drinks, that is, less of what marks a pro-inflammatory diet.
• High-quality protein from fish, organic meat, quark, yoghurt, cheese, mushrooms or tofu for satiety and metabolism.

Schlanke Tanne comes in two variants at the house – as Schlanke Tanne Drei with three meals, and as Schlanke Tanne Intervall, which combines low carb with a 16-hour eating break. For home, the house's own Schlanke Tanne Zuhause approach describes how to carry this way of eating into everyday life, with one lazy day a week and no guilty conscience. Which variant suits whom is discussed in the medical nutritional consultation at the Tannerhof – the individual is at the centre, not a rigid plan.

The Tannerhof approach: Aesthetics between gut and skin

The Aesthetics health programme brings together the two sides of this story: the inner side of nutrition and the outer side of skincare. The nutritional basis is Schlanke Tanne Low Carb, and the focus is on the skin-gut axis. It is explicitly not a beauty promise and not an aesthetic-surgical approach, but a medically supervised path that begins with nutrition.

Part of the medical side is that the house does not view the skin in isolation. The physical examination at the Tannerhof includes bioimpedance analysis, which measures body composition by water, muscle and fat. The broad range of therapies – massages, wraps, baths, breathing and movement therapies – is available alongside, depending on the stay and medical agreement.

The outer side is handled by natural cosmetics, and deliberately regional ones. The Tannerhof uses only two labels: Pharmos Natur from Bernried and Marias from Salzburg. The skin treatments come from these lines, such as the Roseléne treatment with aloe vera lipids, in which cleansing, an intensive peel, an individual special mask, a hand and arm massage and a finishing care routine work together, or the Sesamé treatment with aloe vera and cold-pressed black sesame oil. The relevant page gives an overview of the full range of treatments.

What emerges is an approach that joins two directions without elevating either: the nutrition that starts in the gut and can act on the skin via the axis, and the care that tends the skin from outside. The body nourishes itself from within – in the light of the gut-skin axis, this old Tannerhof saying takes on a very concrete meaning.

Discover beauty from within at the Tannerhof

At the Naturhotel Tannerhof, beauty from within is not a promise but a stance: begin with nutrition, take the gut seriously as a partner, and complement the skin with regional natural cosmetics. It is set in Bayrischzell, between alpine meadow, mountain stream and the view towards the Wendelstein – my hideaway in the mountains as the frame for a break in which you come to rest. Anyone who wants to look more closely at the approach of Schlanke Tanne Low Carb, the skin-gut axis and natural cosmetics, and book online, will find it in the Aesthetics programme.