Whether kimchi or sauerkraut – fermented products are currently more popular than ever due to their health benefits. A new study now shows that they can even be real stress killers. What you need to know.

Fermented foods are trendy. Kimchi, Kombucha, sauerkraut and Co. are currently experiencing a real hype on Instagram and Co. – and not without reason: During fermentation, food is preserved without heat, so vitamins, minerals and secondary plant substances are preserved with all their positive effects. Lactic acid bacteria are also produced in the ferment, which have a probiotic effect on the intestines.

The probiotic effect in particular is said to be decisive for our well-being – and can even reduce stress naturally. This is shown by new studies by the “APC Microbiome”, research institute of University College Cork in Ireland. As part of a study, scientists examined the probiotic effect of fermented foods on the well-being of 45 healthy people between the ages of 18 and 59.

They divided the subjects into two groups, one of which was fed the so-called psychobiotic diet. The control group followed general dietary recommendations. The psychobiotic diet is as follows:

The result after just four weeks: the subjects who followed the psychobiotic diet felt less stressed than the control group. They also slept better than before.

The scientists attribute the changes to the mutual effect of the so-called gut-brain axis. The gut-brain axis is the connection between the gut and the brain, which is primarily via the vagus nerve in the brain. Through the neuronal networking of the organs, the gut and brain communicate with the help of various messenger substances. If there is an imbalance in the intestines, this can have a corresponding effect on the overall well-being – simply because 80 percent of the immune system is located in the intestines.

According to the study authors, a subtle change in the composition and function of the microbes in the gut of the test subjects could be detected. “We observed significant changes in the amount of certain key chemicals produced by these gut microbes,” they write in the study.

There are a total of around 100 trillion germs in the intestines. The beneficial bacteria sometimes produce vital enzymes, vitamins and amino acids and ‘filter’ pollutants from the body. Due to their probiotic effect, fermented foods promote the development and maintenance of a healthy intestinal flora with beneficial bacteria. Prebiotics – a special type of dietary fiber, which the test subjects also ingested through their diet, also serve as an energy source for the beneficial intestinal bacteria and promote their growth. The interaction of prebiotics and probiotics is therefore elementary for a healthy intestinal environment.

According to the scientists, due to the small number of test persons, further research is necessary to test whether the observed effects can also be transferred to the general public. It is also unclear “whether these results can also be repeated in people with stress-related disorders such as anxiety and depression”.

In any case, it is beneficial for the variety in the intestine, digestion and general well-being to regularly include fermented products in the diet. They are now even attributed a colon cancer-lowering effect, and they are also said to be able to reduce symptoms of inflammatory diseases.

Typical fermented foods are:

The longer a food is fermented, the more organic acids such as lactic acid, trace elements and vitamins are produced. Kimchi or sauerkraut, for example, are rich in vitamin C, beta-carotene and B vitamins. The lactic acid bacteria convert sugar into acid, which not only makes the food more durable, but also makes it easier to digest.