The microbiome and the connection between the gut and the brain is well known, but what exactly they are is not always entirely clear. You may know that some bacteria are involved and that the "gut" plays a role, but the details beyond that can be a bit confusing.
The microbiome may sound complicated, but it is actually a fairly simple concept to understand. However, what is not simple is its role in many different aspects of our health. Science is only scratching the surface of the many ways the bacteria that live in our gut affect our health, and the sooner we understand them, the better we will get.
What is the microbiome?
We are facing the bacterial environment of the intestine, specifically the large intestine in normal situations. Bacteria that live in the mouth are also considered by some people to be part of the gastrointestinal tract, and therefore also the microbiome.
Microbiome bacteria include thousands and thousands of different types of species, not just one or two types. There is no way to determine the exact number, but it is known that there are millions of bacteria in the intestine.
For years, it was thought to act as a "fingerprint", and that each person had their own unique set of bacteria within their microbiome. Doctors now know that the microbiome is a dynamic and constantly changing environment . In fact, it is so dynamic that the microbiome right now could be very different from the one in an hour.
What factors affect it?
Factors that affect and change include everything from the amount you sleep to your stress levels, to what medicine you take and the food you eat.
Food
All kinds of things shape our gut bacteria, but the food we eat is probably the most important.
Processed and refined foods, like meats, sugars, and alcohol, can have a negative effect. After just five days of eating a diet high in animal fats and low in fiber, people experienced an increase in bile-tolerant bacteria , which are linked to inflammatory bowel disease, in a January 2014 study in Nature. .
So switching to a high-fiber diet with complex carbohydrates produces a greater diversity of gut bacteria, more fiber-loving bacteria, and lower markers of colon inflammation, according to a June 2018 study in Cell Host and Microbe.
Probiotics
Probiotics are live microorganisms that we absorb and are meant to be "good" bacteria in our intestines. These can be found in both supplements and foods.
Those like kimchi , kombucha , yogurt, sauerkraut and tempeh , have live bacteria that are beneficial to our intestines.
Most people will benefit from a high fiber diet that includes probiotics, to encourage the growth of good bacteria. But pay attention to how your body responds to those foods: Some people, for example, are sensitive to FODMAP, a food group that includes many fruits, vegetables, and grains. If you notice that a particular food or food group causes excessive gas or bloating, you can avoid it.
Prebiotics
Prebiotics encourage the growth of friendly intestinal bacteria, so they act as food for the "good" probiotics in our intestines.
The microbiome lives off of undigested food in our intestines, so things that we cannot digest and absorb become food for the bacteria in the microbiome. Based on what we eat, some species of bacteria in the microbiome will flourish more than others because we have given them what they prefer.
Insoluble fiber is especially important in stimulating the growth of good bacteria in the microbiome. For more prebiotics, add these foods to your diet:
- Oats
- Asparagus
- Bananas
- Lion teeth
- Leeks
- Onions
- Garlic
- Beans
- Sweet potato
Other factors
Almost every action in your life also affects your microbiome, from how long you sleep to how you manage stress. For example, sleep deprivation was linked to negative changes in the microbiome, while adequate sleep was linked to a more diverse microbiome environment, according to an October 2019 study in PLOS One.
Genetics may also play a role in shaping the bacteria that make up the microbiome, according to a November 2014 article in the journal Cell, though to what extent, and how much we can change it with our own actions, remains unclear.
What is the gut-brain connection?
The microbiome is also connected to mental health, but a better term than "gut-brain connection" is "brain-gut-microbiome connection." The brain can affect the intestine and modify bacterial behavior in the intestine, and vice versa.
For example, bacteria in the gut can release chemicals that modify neurons in the brain, which will then release chemicals like serotonin, which can affect your mood. We know that this connection extends to bacteria and bacteria to us.
But while we know that the connection works both ways, that our brains can affect our gut, and our gut can affect our brains, the details of this connection are not too clear yet.
A pilot study, published in April 2018 in the Journal of Neurogastroenterology and Mobility, found a link between irritable bowel syndrome (IBS) and subjective well-being, but how mood and gastrointestinal symptoms affect each other needs more research. .
