He is increasingly becoming a superstar: the gut. Ongoing research confirms the importance of balanced microbial colonization of our largest organ for overall health. The "good" bacteria such as Bacteroides, lactic acid bacteria or Bifidokeime should not be from the "bad", z. B. the Firmicutes, are overgrown. But they are beautiful too? "Yes, because health and attractiveness are closely related, and the skin is the mirror of our gut," says dermatologist and author Dr. med. Michaela Ax-Gadermann ("Beautiful with gut", southwest publisher, € 17.50). The expert talk. WOMAN: You say the gut is an inner beauty salon. How does this work? Axt-Gadermann: A healthy gut produces beneficial substances such as hyaluronic acid and ceramides, which we know as cosmetic ingredients, as well as substances that protect us from UV radiation. The right microbiome, so the bacterial colonization, can reduce wrinkles. The core ingredient for this are antioxidants and phytochemicals. Particularly valuable are the polyphenols, the dyes in the plants. You already know that for a long time. What is new is the realization that the intestine can only absorb these nutrients if its bacterial flora works well and splits them up. If she does not do that, simply slip through. WOMAN: Does that mean a healthy diet does not make sense if the gut bacteria are not working properly? Ax Gadermann: First of all yes, because the body can not use them. But it still makes sense because there is an interaction. Polyphenols promote the growth of beauty germs and inhibit the proliferation of harmful microorganisms. The more colorful foods we eat, the more of the good microbes settle down. Important is the regularity. Because it takes a few weeks until a first change shows up. WOMAN: What else do you have to pay attention to? Ax Gadermann: The intestine regulates the pH of the skin. He should be angry, but he gets older as he grows older. The higher it is, the more enzymes are activated that destroy collagens. If you manage to lower the pH of the skin to below five via the intestinal flora, the activity of these enzymes is stopped. WOMAN: Hormone production is also partly regulated in the stomach. What influence do hormones have on beauty? Ax Gadermann: Estrogen and testosterone shape our figure, build muscle and tone the skin. It also needs a healthy bowel. It also breaks down stress hormones such as cortisol or adrenaline, which protects against micro-inflammation, and produces happiness and satisfaction hormones such as dopamine or serotonin. One sleeps better, can deal with critical situations more relaxed. This affects the psyche positively, it looks better. WOMAN: And all this works with enough polyphenols? Should we just eat fruits and vegetables now? Ax Gadermann: Fruits and vegetables are especially important for the direct optical effects. But our gut is also a hub of health. There are tens of billions of germs in it that, as a whole, help to keep the metabolism running. It is important that one feeds all. Therefore you should eat as varied as possible. That is quite practical in itself. Providing the bacteria with a rich buffet, they serve themselves as needed. The good sprout and keep the bad at bay. The prebiotics are especially popular as food. WOMAN: Can you explain that? Ax Gadermann: These are certain dietary fiber such as inulin or resistant starch. These are found in legumes, onions, garlic and generally all leeks, Jerusalem artichokes, parsnips, oatmeal or flaxseed. This is especially true in cold potatoes and rice. By heating and cooling, the starch changes in it. This is a true feast for the bacteria. Do not worry, you do not have to change the entire diet. But these things should be included more often in the diet. For this, one dispenses with ready meals and processed foods. WOMAN: What do they do in the gut? Ax Gadermann: Fast food about contains the wrong fat, which favors inflammatory germs and obesity. Additives such as emulsifiers are suspected to make the mucus layer in the intestine water-soluble and thus to dilute. Then substances enter the body, which have lost nothing there. Sweeteners change the microbiome so that more sugar is removed from the diet, which is bad for the blood sugar level. And preservatives do the same to us in food. They inhibit the growth of germs. But that is counterproductive, especially in the gut. WOMAN: Antibiotics are also bad for the intestine and therefore for the beauty? Ax Gadermann: Correct. They kill everything, including the good germs. If you have to take them, then you must combine them with probiotics, ie intestinal cultures. There are several good products on the market, I was involved in the development of one myself. This includes probiotics and prebiotics. We are also exploring new exciting application possibilities. WOMAN: Which would that be? Ax Gadermann: You can also treat the skin with these intestinal germs. We did a first controlled study, in which we dissolved a bacterial cure in warm water. Ten patients with eczema bathed these for ten minutes each in the liquid. Already after a few days a clear improvement was recognizable. Of course, this research is still in its infancy. But in the US, probiotic cosmetics, so products with intestinal bacteria, already a big topic.