Gut Microbiome 101: How the Gut is the Key to Health

by Helen Marshall

Primalista Tammy Rose-Townsend

What Is the Gut Microbiome? 

All human beings have bacteria in and on their body. In fact, research has shown that the human body is composed of more bacteria than cells. A healthy human body is actually swarming with microorganisms inhabiting every nook and cranny of the body. However, it is in our gut (the gastrointestinal tract), that we can find the largest collection of microorganisms.

These microorganisms are a community and as such make up our gut microbiota. Combine the microbiota, the products it makes, and the entire environment it lives within and we have a microbiome.

The human microbiome (all of our microbes’ genes) can be considered a counterpart to the human genome (all of our genes).

Every human being has a gut microbiota and the composition for each person is unique.

Regardless of the composition, the microbiota has the same physiological functions with a direct impact on the health of the human body. Some of the functions are:

  • Helps the body to digest certain foods that the stomach and small intestine haven’t been able to digest.
  • Helps with the production of vitamins B and K.
  • Helps the body combat other microorganisms that would otherwise harm the gastrointestinal tract.
  • Plays an important role in the immune system, primarily by performing as a barrier.
  • A healthy and balanced gut microbiota is key to ensuring proper digestive functioning.

These are vital and important functions of the human body and the immune system. Some researchers have said that up to 90 percent of all diseases can be traced in some way back to the gut and health of the microbiome.

Poor gut health can contribute to many diseases and disorders such as leaky gut syndrome, autoimmune disease, arthritis, dementia, heart disease, and cancer.

What is surprising to many is the fact that health, fertility, and longevity are all reliant on the balance of organisms and bacteria living within the gut.

Every human being has the power to shape their own microbiome, which in turn adapts to changes in their environment. For example, the foods that are eaten, sleeping patterns, the amount of bacteria the person is exposed to every day, and the level of stress the person lives with all help to establish the state of the gut microbiota.

Which brings us to the good news: you can positively affect your microbiome through diet, physical exercise, sleep, and stress management.

Why They Call the Gut Microbiome the Body’s Second Brain 

Most people think of bacteria within the body as a cause of getting sick or developing certain diseases, but the reality is that at all times there are billions of beneficial bacteria within all of us. Bacteria make up our gut microbiome, an internal ecosystem that benefits our gut health and the immune system.

Each of us has a unique gut microbiome. The microbiome is defined as a “community of microbes.” And the majority of the bacterial l species that make up our microbiome live in our digestive system. According to the Department of Chemistry & Biochemistry at the University of Colorado, “the human microbiota consists of the 10–100 trillion symbiotic microbial cells harbored by each person, primarily bacteria in the gut. The human ‘microbiome’ consists of the genes these cells harbor.”

The scientific community recognizes the important role that bacteria have in supporting a strong immune system. And that some bacteria are vital for boosting immunity, keeping our digestive systems running smoothly, our hormone levels balanced and our brains working properly.

This leads us to our Second Brain

If you have ever “gone with your gut” to make a decision or felt “butterflies in your stomach” when nervous, you’re likely getting signals from an unexpected source: your second brain.

Hidden in the walls of the digestive system, this “brain in your gut” is having a major impact on the field of medicine and the understanding of the links between digestion, mood, health and even the way you think.

Scientists call this “second brain” the enteric nervous system (ENS). It is two layers of more than 100 million nerve cells lining your entire gastrointestinal tract – from the esophagus to the rectum.

As explained by Jay Pasricha, M.D., director of the Johns Hopkins Center for Neurogatroenterology, whose research on the enteric nervous system is respected internationally, “The ENS doesn’t seem capable of thoughts we know, but it communicates back and forth with our big brain – with profound results. Its main role is controlling digestion, from swallowing to the release of enzymes that break down food to the control of blood flow that helps with nutrient absorption to elimination.”

The important piece of information at this point is that the ENS has a direct effect on our emotional and mental well-being. It was once thought that our emotions such as anxiety and depression were the contributing factors to various gut problems. But the researchers today are finding evidence that irritation in the gastrointestinal system is sending signals to the central nervous system (CNS) and that is what is triggering mood changes and swinging emotional levels.

Why is this important?

When we know the cause of a problem we can then work to fix or heal the cause. Understanding that our gut health is vital to our brain health means that we can be a part of the solution to our emotional and mental challenges.

This doesn’t mean that eating certain foods will prevent us from being angry. What it does mean is that if our mood swings are wide or we suffer more than just ‘the blues’ and actually experience depression, we can be a part of the solution by changing our eating habits and reducing the stress in our lives to take care of our gut, which in turn will take care of our mental and emotional health.

How Gut Bacteria Impacts Your Health 

Most of us are aware that the bacteria in our gut plays an important role in digestion. When the stomach and small intestine are unable to digest certain foods we eat, gut microbes jump in to offer a helping hand, ensuring we get the nutrients we need.

In addition, gut bacteria are known to aid the production of certain vitamins like B and K and play a major role in immune function. This is leading researchers to study the impact that gut bacteria has on our health.

Research suggests that the gut bacteria in healthy people are different from those with certain diseases. Every human being has a gut microbiota (community of bacteria) that is unique. People who are sick may have too little or too much of a certain type of gut bacteria, or they may lack a variety of bacteria.

Scientists have begun to draw links between the following illnesses and the bacteria in your gut:

Obesity, type 2 diabetes, and heart disease: 

Your gut bacteria affects the body’s metabolism. They determine how many calories you get from food and what kinds of nutrients you receive. Too much of the wrong gut bacteria can make you turn fiber into fatty acids. This can cause fat deposits in your liver, leading to something called metabolic syndrome – a condition that can lead to type 2 diabetes, heart disease, and obesity.

Inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis: 

It’s believed that people with these conditions have lower levels of certain anti-inflammatory gut bacteria. The exact connection is unclear, but researchers think that some bacteria may make your body attack your intestines and set the stage for these diseases.

Mental Health:

According to the American Psychological Association (APA), gut bacteria produce an array of neurochemicals that the brain uses for the regulation of physiological and mental processes, including memory, learning, and mood. And, 95% of the body’s supply of serotonin is produced by gut bacteria. Which means that gut bacteria have been associated with a number of mental health problems that include anxiety disorders and depression.

The Connection Between Your Microbiome And Your Diet 

We’ve all heard ‘you are what you eat’.

Well, it may be better stated as – your gut health is dependent on what you eat. And your gut health has a direct impact on your physical and mental health.

A healthy human body has microorganisms inhabiting every nook and cranny. As mentioned before, it is in our gut, the gastrointestinal tract, that we can find the largest collection of microorganisms.

Every human being has a gut microbiota (community of bacteria) that is unique.  People who are sick may have too little or too much of a certain type of gut bacteria, or they may lack a variety of bacteria.

The good news is you have the ability to affect the balance of your gut bacteria and it can be done through diet.

Knowing that diet is important is one thing, but consciously eating foods that support good gut health is even more important. And, it’s not as difficult as you might think.

Medical Disclaimer:

The information on this site has not been evaluated by the FDA or the TGA and is not to be taken as medical advice. I am not a doctor and only offer up the personal experience of myself and my family. All material on this website is provided for information only and may not be construed as medical advice or instruction. No action or inaction should be taken based solely on the contents of this website, instead, readers should consult with the appropriate health professional in any matter relating to their health and well-being. Readers who fail to consult with the appropriate health professional assume the risk of any injuries.


Author: Primalista Tammy Rose-Townsend

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