When you hear the word microbiome, chances are you may be thinking about your gut.
True, your gut is part of your microbiome, but your microbiome is much more vast and important to your health than you might realize.
“Just like any other environment on the planet, our bodies have their own ecosystems -- made up of 100 trillion microorganisms, or microbes, that live in and on our bodies," says Rachael Buck, PhD, Abbott's lead research scientist and resident gut health expert. "These include bacteria, fungi, viruses and other types of tiny organisms. It’s so large in fact, that the genes of microbes outnumber our body’s genes by 100 to 1."
Although microbes are everywhere, they’re found in large quantities in areas of the body where hair grows -- like on your head or your underarms. Dense populations of microbes are also found in moist areas and in soft tissues -- like your gums, the inside of your cheeks, and on your tongue.
The Gut Microbiome Explained
When it comes to the microbiome, the large intestine (or, the colon) receives the most attention because it contains the highest concentration and greatest diversity of microbes in the entire body. The large intestine is lined with a layer of mucus and the microbes that live there form a gut biofilm. The biofilm contains an array of different microbes that carry out different tasks in your body and also work together to keep you healthy.
What’s even more fascinating is that each and every person has a unique make-up of microbes.
“What determines the different types of microbes in a person is a result of ones genes, age, gender, diet, hygiene, and even the climate you live in and your occupation,” says Buck. “In fact, studies show that the gut microbiome affects everything from pain, mood, sleep and stress, to how our bodies use the food we eat and how we fight off infection.”
How the Microbiome Affects Us
Here are four ways in which your microbiome can impact the rest of your body and your mind.
When it comes to our diet, our gut health affects what we eat and vice versa – what we eat affects our gut health. The microbes in our gut make small molecules that travel throughout the blood stream. These molecules affect how our bodies store nutrients, use sugar, regulate our appetites, and control our weight. The foods we eat also play a significant role when it comes to optimal gut health.
So-called “Western diets” – diets that are high in fat and in highly-refined carbohydrates or sugars – can cause the good and bad bacteria in the gut to become unbalanced. In fact, people who eat large quantities of these highly-processed foods can develop leaky gut syndrome, a condition in which the tight junctions in the large intestine open up and allow bacteria and their toxins to get through. This, in turn, can elicit an inflammatory response.
Emerging science also suggests that consuming too much of these foods also erodes the mucus layer that protects the intestinal cells from coming in direct contact with the gut microbes and contributing to inflammation.
2. Sleep and Mood
People often say “it’s all in your head,” but research shows that all that angst may actually start in the gut.
Dubbed the second brain, the enteric nervous system within the gut contains 30 types of neurotransmitters and 100 million neurons. Ninety-percent of serotonin, which helps to produce melatonin, the “sleep hormone,” is located in the gut. There is also 400 times more melatonin in the gut than there is in the brain.
In recent years, studies have looked at the “gut-brain axis” and how gut health can affect pain, sleep, depression and anxiety. In fact, a recent pre-clinical study suggested that eating probiotic-rich yogurt may be able to reverse depression.
3. Inflammation and Infection
The gut microbiota also works to keep our bodies healthy because the microbes act to crowd out harmful bacteria such as those that cause infections. The gut also contains bacteria that release compounds which can lower inflammation throughout the body and prevent an attack on the immune system.
In addition to helping to keep our mind and body healthy – research has shown the microbiome also works to keep our skin healthy. Oily parts of the body – like the back or the face – tend to have fewer types of microbes because oil is anti-microbial, which keep bacteria out.
These microbes also transform oils in the skin into natural moisturizers to keep the skin soft and supple. And when skin is moisturized, it also prevents bacteria from invading our bodies.
To learn more about how to keep your gut healthy at every age, check out this article.