The gut is a true marvel: this is how it affects the body

More than just a digestive organ

When we receive troubling news, we first have to digest it. Injustice is difficult to stomach. An unkind remark leaves a bad taste in our mouth. If we are particularly tense and stressed, we get diarrhoea: the way that the digestive tract has entered into our language, and also how it reacts to our state of mind, is telling. Proof enough that the gut should not be reduced to its digestive function.

Gut: the Inside Story

With Julie Enders’ book, Gut: The Inside Story of Our Body's Most Underrated Organ, published in 2014, the topic finally came to reach social acceptance, and now even the most elevated circles may be heard discussing the marvels of the gut. And rightly so – because the intestine is the largest immune organ in our body, includes as many nerve cells as the spinal cord, and digests around 30'000kg of solid food over the course of a lifetime.

Intestinal flora and related bacteria

The intestinal flora – consisting of trillions of bacteria – has a fundamental influence on our state of health. This is because approximately 100 trillion intestinal bacteria train our immune system and protect the body from unwanted germs, assist in the formation of vitamins and neutralise toxins. No less than 80 percent of our entire immune system is in the intestine, with its millions of nerve cells constantly collecting information about our general condition.

You are what you eat

Even obesity cannot be viewed in isolation from the intestinal flora: certain bacteria in the intestines can cause some people to become fat, even though they don’t consume more calories than thinner people. The intestines of overweight people often contain more bacterial genes responsible for breaking down carbohydrates, for example. However, we don’t have to be victim to our bacteria and their effect on our mood. What we eat and how we live influence our intestinal flora. Bacterial researchers believe, for example, that different bacteria survive in the intestine of people dealing with constant stress, than in those with a relaxed lifestyle. Although these bacteria cope with the stress, they dampen the person’s mood.

The gut and brain are linked

It is now beyond any doubt that our gut influences our well-being. The truth is that the intestine – via a nervous system and its vast surface area – is closely linked to the brain. This is illustrated by the fact that humans know exactly what the needs of their digestive tract are, i.e. when they should go to the toilet. Conversely, heightened anxiety, for example, affects activity in the large intestine: it no longer has enough time to absorb fluid, and the result is diarrhoea. This type of diarrhoea is the intestine’s strategy of coping with the increased energy required by the brain due to stress – it wants to get rid of the food early.

The way the gut and brain work together demonstrates that the human being is a complex ecosystem. Hormones released in the intestine directly influence our feelings and mood, while hormones produced in the brain affect intestinal activity. In positive cases, a person has butterflies in their stomach, in negative cases, they have a runny tummy. «Our self is created in our head and belly», is how Enders puts it in a nutshell. For people with irritable bowel syndrome, the connection between the intestine and the brain can lead to serious problems – these people suffer above-average anxiety or depression. The same applies to people with chronic abdominal inflammation.

Well-being is not just in the head

Pleasure, uncertainty, fears and bad moods don’t come from the head alone. Reason enough to pay more attention to your gut – and not only when it no longer functions as it should.