Gut: The Inside Story of Our Body's Most Underrated Organ

While some of us might be sitting around thinking “Nobody cares about me!”, our heart is currently working its seventeen-thousandth twenty-four-hour shift—and would have every right to feel a little forgotten when its owner thinks such thoughts.

Looking closer at human beings, it becomes clear that each of us is a world of our own. Our forehead is a breezy meadow, our elbows are arid wastelands, our eyes are salty lakes, and our gut is the most amazing giant forest ever, populated by the weirdest of creatures.

We humans have known since time immemorial something that science is only now discovering: our gut feeling is responsible in no small measure for how we feel. We are “scared shitless” or we can be “shitting ourselves” with fear. If we don’t manage to complete a job, we can’t get our “ass in gear.” We “swallow” our disappointment and need time to “digest” a defeat. A nasty comment leaves a “bad taste in our mouth.” When we fall in love, we get “butterflies in our stomach.” Our self is created in our head and our gut—no longer just in language, but increasingly also in the lab.

More than 95 percent of the world’s bacteria are harmless to humans. Many are extremely beneficial. Disinfectants have no place in a normal household. They are appropriate only if a family member is sick or the dog poops on the carpet.

Sweetness is not in itself unhealthy, we simply eat only the most unhealthy kind of sweetness.

Scientists are cautiously beginning to question the view that the brain is the sole and absolute ruler over the body. The gut not only possesses an unimaginable number of nerves, those nerves are also unimaginably different from those of the rest of the body. The gut commands an entire fleet of signaling substances, nerve-insulation materials, and ways of connecting. There is only one other organ in the body that can compete with the gut for diversity—the brain. The gut’s network of nerves is called the “gut brain” because it is just as large and chemically complex as the gray matter in our heads. Were the gut solely responsible for transporting food and producing the occasional burp, such a sophisticated nervous system would be an odd waste of energy. Nobody would create such a neural network just to enable us to break wind. There must be more to it than that.

As it happens, the higher the hygiene standards in a country, the higher that nation’s incidence of allergies and autoimmune diseases. The more sterile a household is, the more its members will suffer from allergies and autoimmune diseases. Thirty years ago, about one person in ten had an allergy; today, that figure is one in three.

The aim of cleaning, then, should be to reduce bacteria numbers—but not to zero. Even harmful bacteria can be good for us when the immune system uses them for training. A couple of thousand Salmonella bacteria in the kitchen sink are a chance for our immune system to do a little sightseeing. They become dangerous only when they turn up in greater numbers. Bacteria get out of hand when they encounter the perfect conditions: a protected location that is warm and moist with a supply of delicious food.

Every day we live and every meal we eat we influence the great microbial organ inside us - for better or for worse.

Those people who post pictures of their dinner on Facebook, only to be disappointed by the lack of “likes” from friends, are simply trying to appeal to the wrong audience. If there were such a thing as Facebug (Facebook for microbes!), a picture of your dinner would provoke an excited response from millions of users—and shudders of disgust from millions more. The menu changes daily: useful milk digesters contained in a cheese sandwich, armies of Salmonella bacteria hiding in a delicious dish of tiramisu.

Our stomach sits much higher in our abdomen than we think. It begins just below the left nipple and ends below the bottom of the ribcage on the right. Any pain felt farther down than this lopsided little pouch cannot be stomachache. Often, when people say they have stomach problems, the trouble is actually in the gut. The heart and the lungs sit on top of the stomach. This explains why we find it more difficult to breathe deeply after eating a lot.

Almost nothing influences our gut bacteria as much as the food we eat. Preboiotics are the most powerful tool at our disposal if we want to support our good bacteria - that is, those that are already there and are there to stay.

The gut has not only a remarkable system of nerves to gather all this information, but also a huge surface area. That makes it the body’s largest sensory organ. Eyes, ears, nose, or the skin pale by comparison. The information they gather is received by the conscious mind and used to formulate a response to our environment. They can be seen as life’s parking sensors. The gut, by contrast, is a huge matrix, sensing our inner life and working on the subconscious mind.

The fructose intake of the average American is currently close to 3 ounces (80 grams) a day. Our parents’ generation, consuming just honey on their toast, far fewer processed foods, and a normal amount of fruit, took in no more than ½ to 1 ounce (only around 16 to 24 grams) a day.

our gut brain possesses the same neural receptors as the brain in our head. So, antidepressants automatically ‘treat’ both brains.

Mindful yogurt manufacturers often use bacteria that produce more dextrorotatory (right-turning) than levorotatory (left-turning) lactic acids. Molecules of the two kinds of lactic acid are mirror images of each other. Feeding the human digestive system with levorotatory lactic acid molecules is like giving a left-handed pair of scissors to a right-handed person: they’re hard to handle. That is why it is a good idea to pick yogurt from the supermarket shelves that states on the container: “Contains mainly dextrorotatory [or right-turning] lactic acid.

globalization and air transport mean that we are now exposed to a previously unheard-of overabundance of fruit. Pineapples from the tropics nestle on our supermarket shelves in the middle of winter, next to fresh strawberries from Mexico, and some dried figs from Morocco. So, what we label a food intolerance may in fact be nothing more than the reaction of a healthy body as it tries to adapt within a single generation to a food situation that was completely unknown during the millions of years of our evolution.

Doctors believe that straining too much or too often on the toilet can also seriously increase the risk of varicose veins, a stroke, or defecation syncope—fainting on the toilet.

Simple carbohydrates such as sponge cake, rice, or pasta make it through to the small intestine pretty quickly. There, they are digested and rapidly cause an increase in the levels of sugar in our blood. The doorman detains proteins and fats in the stomach for considerably longer. A piece of steak may easily be churned about for six hours before all of it has disappeared into the small intestine. This explains why we often fancy a sweet dessert after eating meat or fatty, fried foods. Our blood sugar levels are impatient and want to rise quickly, and dessert provides a quick blood sugar fix. Meals rich in carbohydrates may perk us up more quickly, but they do not keep us feeling full for as long as meaty or fatty meals. Small Intestine When the mini-morsels reach the small intestine, the real process of digestion begins. As it passes through this tube, the motley cake mush will almost completely disappear into its walls—a bit like Harry Potter on Platform 9¾. The small intestine pluckily pounces on the piece of cake. It squeezes it, hashes it up from all sides, wiggles its villi in what we might now call the cake chyme, and when it is thoroughly mixed, moves it on down the digestive line. Under the microscope we can see that even the microvilli help it along! They move up and down like tiny trampling feet.

The important thing is not to reduce the human body to a two-dimensional cause-and-effect machine. The brain, the rest of the body, bacteria, and the elements in our food all interact with each other in four dimensions. Striving to understand all these axes is surely the best way to improve our knowledge. However, we can more easily tinker with bacteria than with our brain or our genes-and that is what makes microbes so fascinating.

Even the most conscientious of cleaners would not dream of taking a mop to the forest floor.

Count Dracula. A genetic defect has been identified in his home country, Romania, that results in symptoms that include a lack of tolerance to garlic, sensitivity to sunlight, and the production of red urine.

So, what we label a food intolerance may in fact be nothing more than the reaction of a healthy body as it tries to adapt within a single generation to a food situation that was completely unknown during the millions of years of our evolution.

By preferring cooked food, the body outsources the first part of the digestive process.

Sugar is the only substance our body can turn into fat with little effort.

It is now generally accepted in scientific circles that people with certain digestive problems often suffer from nervous disorders of the gut.

Anyone who suffers from anxiety or depression should remember that an unhappy gut can be the cause of an unhappy mind. Sometimes, the gut has a perfect right to be unhappy, if it is dealing with an undetected food intolerance, for example. We should not always blame depression on the brain or on our life circumstances - there is much more to us than that.

I'm sometimes shocked by the way scientists huddle behind closed doors to discuss important research results without informing the public about them at all. Academic caution is often preferable to premature publication, but fear can also destroy opportunities.

So far, very few treatments have been scientifically proven to be effective. One of those is hypnotherapy. Really good psychotherapy is like physiotherapy for the nerves. It eases tensions, and teaches us how to move in a more healthy way — at the neural level. Because