The gut-brain axis

How smart is my gut?

How much does our gut actually remember, and how exactly is it connected to the brain? The link between gut and brain has been studied for quite some time now, and science has uncovered many fascinating insights. We wanted to take a closer look at the gut-brain axis – and asked an expert.

Dr. Adolf Heschl is a biologist and has been working at the Institut Allergosan for eight years as an expert in the field of probiotics. We had the opportunity to ask him a few questions.

What is meant by the gut-brain axis? 
It refers to the close connection and intensive exchange of information between the gut and the brain – in both directions. A central element of this communication is the nervous system. Around 100 million nerve cells are located in the digestive tract – 4–5 times more than in the spinal cord.

Since when has science known about the connection between the gut and the brain? 
The fact that there are close functional relationships between the gut and the brain has been known in medicine since the discovery of the vagus nerve. However, that the composition of the gut microbiome also plays an important role is an insight that only emerged about 10 years ago. One of the key publications in this field was an article by John Cryan, one of the pioneers in this research (here you can find the article). Around the same time, we also conducted our first studies with OMNi-BiOTiC® STRESS Repair, which, in addition to its anti-inflammatory effects, also showed mood-enhancing benefits.

The gut is sometimes described as our “second memory.” Do you agree with this description? 
This is true insofar as the variety of experiences that the digestive tract accumulates over time with different foods are passed directly to the brain and stored there. In this way, the gut teaches us which foods are good for our body and which are better avoided. Without this transfer of information, metabolism would eventually become imbalanced and severe illnesses could develop.

What role do hormones play in the gut-brain axis? 
The latest research has shown that the diversity of a person’s gut flora correlates with the concentration of sex hormones in the blood. Men with greater bacterial diversity had significantly higher testosterone levels, while women had correspondingly higher estrogen levels.

How can I strengthen my gut-brain axis? Does it even need strengthening? 
Strengthening the gut-brain axis pays off in two ways. On the one hand, digestion and immune defense function more effectively, and on the other, brain activity can flourish and become more creative. Sleep depth improves during recovery phases, which benefits both the brain and digestion. With regular intake of an OMNi-BiOTiC® preparation, a positive upward spiral can be triggered, gradually lifting people even from mild depressive states. 
Ideally, such a regimen begins with a probiotic that can quickly displace problem-causing bacteria from the digestive tract. OMNi-BiOTiC® 10, taken twice daily for four weeks, helps clear the gut of pathogenic bacteria whose metabolic byproducts, such as ammonia and hydrogen sulfide, place a burden on the brain. In parallel, the intake of concentrated humic acids (Activomin) is recommended to efficiently bind bacterial toxins (produced by putrefactive bacteria for defense). A third step is the regular use of a suitable fiber supplement (prebiotic) that promotes beneficial bacteria – such as Akkermansia muciniphila, which stimulates mucus production, and Faecalibacterium prausnitzii, which reduces inflammation. OMNi-LOGiC® PLUS combines three different fibers (FOS, GOS, glucomannan) to stimulate the growth of these key, oxygen-sensitive bacteria. Since the digestive system must first adapt to fiber, it is best to start with a low dose and increase gradually.

How does nutrition influence the gut-brain axis? 
For our gut bacteria to thrive, they need fiber in sufficient quantities. Without it, they cannot produce important metabolites that positively affect gut and brain metabolism – such as short-chain fatty acids (butyrate, propionate, acetate), vitamins (K2, B12), or lactic acid. The WHO currently recommends 30 grams per day. These fibers, whether from diet or prebiotic supplements like OMNi-LOGiC®, should be as varied as possible to promote microbial diversity. Research has shown that bacteria, just like humans, prefer different foods: bifidobacteria love resistant starch, the slimming Bacteroidetes prefer pectins, while Akkermansia thrive on galactooligosaccharides (GOS).

Are there already studies on how Covid-19 affects the gut or the gut-brain axis? 
This question is currently being researched very intensively, and the list of publications is already long. Current findings clearly show: regular intake of a suitable multispecies probiotic not only reduces the likelihood of infection with the virus but also increases the chances of avoiding a severe course of the disease. This also has a protective effect on the brain, as in many cases the virus does not spare it.

Thank you very much for the insightful conversation.