Bloating, gas, constipation, diarrhea, fatigue, or a stomach that suddenly reacts to more and more foods. Many digestive issues that may seem completely different have one thing in common: the intestinal environment has changed.
An enormous ecosystem of bacteria and other microorganisms lives in our intestines, and together they are usually referred to as the gut microbiota/the gut flora. When this ecosystem functions well, the microorganisms help us, among other things, break down parts of our food, produce important metabolites, communicate with the immune system, and protect the intestinal environment.
But just like other ecosystems, the gut ecosystem can also become unbalanced. This is called gut dysbiosis.
What is gut dysbiosis?
Dysbiosis simply means that the composition or function of the microorganisms in the gut has changed in a way that may negatively affect the intestinal environment.
This may, for example, involve:
- reduced microbial diversity
- a decrease in certain beneficial bacteria
- an increase in potentially problematic microorganisms
- altered production of microbial substances
- a changed intestinal environment that favors the wrong microorganisms
It is therefore important to understand that dysbiosis does not mean that you have a single "bad bacterium" that needs to be removed.
The gut functions more like an ecosystem. The goal is not to eliminate all less desirable bacteria; many of them can also be present in a healthy gut without creating an environment in which different microorganisms can live in a functional balance.
Nor is there any exact bacterial composition that defines a perfect gut microbiome. The gut microbiome varies greatly between people and is influenced by factors including diet, age, environment, medication, and lifestyle.
Why are the bacteria in the gut so important?
Gut bacteria do far more than just help with digestion.
When bacteria ferment fibers that we cannot break down ourselves, they produce, among other things, short-chain fatty acids, such as acetate, propionate, and butyrate.
Butyrate, also known as butyric acid, is particularly interesting because it serves as an important energy source for the cells in the colon and is involved in the function of both the intestinal barrier and the immune system. This means that the food we eat does not only nourish us.
It also provides nourishment for the microorganisms that live alongside us.
A varied, high-fiber diet gives bacteria access to different types of fermentable carbohydrates. If, on the other hand, the diet contains very little fiber over a long period, the environment in which the bacteria live also changes. This is one reason why diet plays such a central role in the gut microbiome.
What can cause dysbiosis?
Dysbiosis rarely occurs due to a single factor. Often, several things work together to change the intestinal environment.
Low-fiber and monotonous diet
Our gut bacteria primarily need different types of fiber and complex carbohydrates from plants. Vegetables, fruit, berries, legumes, whole grains, nuts, and seeds contain different fibers and plant compounds that affect the gut microbiota.
If the diet is very limited for a long time and contains little plant-based fiber, the amount of substances that many of our fiber-fermenting bacteria rely on decreases.
Antibiotics
Antibiotics can be life-saving and should of course be used when medically indicated. At the same time, antibiotics do not affect only the bacterium causing an infection; they can also alter parts of the normal gut microbiota.
After a course of antibiotics, the gut microbiota can recover, but the extent and speed vary between individuals.
Stress
The gut and brain communicate continuously through what is known as the the gut–brain axis.
Long-term stress can affect, among other things, intestinal movements, secretion, immune activity, and eating habits. When working on gut health, it is therefore sometimes necessary to look beyond what is on the plate.
Slow intestinal motility
The time it takes for contents to pass through the intestine also affects the environment there. With long-term constipation and slow intestinal motility, the conditions for microorganisms change. Regular bowel function is therefore an important part of a well-functioning intestinal environment.
Infections, certain medications, illnesses, and major dietary changes can also affect the gut microbiota.
Common symptoms of an imbalanced gut
Dysbiosis is not a diagnosis with a specific symptom, and the same complaints can have many different causes. However, common gastrointestinal symptoms that occur in connection with an altered gut microbiota include:
- bloating
- a lot of gas
- constipation
- diarrhea or loose stools
- alternating constipation and diarrhea
- abdominal pain or discomfort
- changes in bowel habits
Research has also identified changes in the gut microbiota in a range of conditions, both inside and outside the gastrointestinal tract.
However, this does not automatically mean that dysbiosis is the cause. The relationship between the gut microbiota and health is often bidirectional: illness can alter the gut microbiota, while an altered gut microbiota may potentially affect the body's physiology.
Dysbiosis and leaky gut – what is the connection?
The bacteria in the intestine live close to the intestinal lining and play an important role in how this protective barrier functions. The intestinal lining can be thought of as a careful gatekeeper: it should allow water and nutrients that the body needs to pass through, while keeping bacteria, toxins, and other substances inside the intestine.
When the gut microbiota becomes imbalanced, this environment can change. The beneficial gut bacteria produce, among other things, substances that help nourish the cells of the intestine and keep the intestinal lining strong. One such substance is butyrate (butyric acid), which are formed when bacteria break down fiber from food.
With dysbiosis, the production of these protective substances may decrease, while the gut environment may become more irritated and inflammatory. This can, in turn, affect the gut barrier, making it more permeable than it should be.
This is called increased intestinal permeability, but is better known as leaky gutDysbiosis and leaky gut are therefore closely connected and can also affect and reinforce each other. In the next article, we take a closer look at what leaky gut means, why it occurs, and how we can support a stronger gut barrier.
How do you build a better gut environment?
When people hear the word dysbiosis, many immediately think of probiotics. But building a well-functioning gut microbiota involves much more than adding a few bacterial strains in a capsule. The most important thing is to create an environment where the bacteria we want to support can actually thrive.
1. Feed the bacteria with fiber
Fiber is one of our most important tools for supporting the gut microbiota.
Aim for variety from sources such as:
- vegetables
- root vegetables
- fruit and berries
- legumes
- whole grains
- nuts and seeds
Different bacteria prefer different types of fiber, which makes variety at least as important as the total amount.
2. Don’t forget resistant starch
Resistant starch largely passes through the small intestine without being broken down and can then be fermented by bacteria in the large intestine. It is found, among other things, in legumes, oats, green bananas, and cooked and cooled potatoes and rice.
3. Eat a colorful variety
Polyphenols are bioactive plant compounds found, among other things, in berries, herbs, spices, cocoa, tea, fruit, and colorful vegetables. There is an exciting interplay between polyphenols and the gut microbiota: bacteria can convert polyphenols, while polyphenols can influence which microorganisms thrive in the gut.
4. Increase slowly if you have a sensitive stomach
More fiber is not always better from day one. Someone with a lot of gas, severe bloating, or long-term digestive problems may need to increase their fiber intake gradually. Otherwise, suddenly going from a low-fiber diet to large amounts of legumes, raw vegetables, and whole grains can cause significantly more gas. The goal is not to push the gut, but to gradually increase its capacity.
The gut needs an ecosystem, not a quick fix
Perhaps the most important thing to understand about dysbiosis is that the gut is changeable.
The gut microbiota is continuously influenced by what we eat, how we live, medications, stress, and our surroundings. This also means that through our everyday choices, we can influence the environment where our gut bacteria live.
Instead of simply asking:
"Which bacterium am I missing?"
it may therefore be more helpful to ask:
"What kind of environment am I creating for my gut bacteria every day?"
Because ultimately, a healthy gut is not about a single bacterium. It’s about an entire ecosystem.
