Why Is Gut Health So Important To Your Immune System?

Gut health is so important to our immune system because our body has 100s of trillions of bacteria, viruses, and fungi, the majority of them being bacteria.  The gut houses 300 to 500 different kinds of bacteria that have about 2 million genes. They are vital to the proper function of the gut and the immune system. Humans have adapted to live with these microorganisms for millions of years.  Most of these microbes are essential for our survival and are harmless except a few which might cause disease.

These microbes are essential to our body and especially the gut where all these microbes call their home. They get all their nutrients from the food we eat and they instead give us protection from disease.  We have a mutual relationship aka symbiosis as in scientific terminology. This is a two-way street where two different species get along so well that they co-exist in the same environment, living together in harmony and helping each other.

Everyone of us is exposed to bacteria when passing through the birth canal of our mothers.  However, there are new studies( 1, ) that indicate that we come into contact with microbes way before we are even born and still in the worm of our mothers. As our bodies grow we get more diverse microorganisms depending on what we feed our bodies.  This diversity of microbes affects our health and well-being in many different ways.

How Do The Gut And Immune Work Together?

After many years of research, it was approximated that 70-80% of the immune system is found in the gut”  Therefore the gut and the immune system work together to protect you against any harmful microorganism.  For example, when you eat unfamiliar food, your stomach starts acting up by feeling nauseous, diarrhea, pain, and, cramping, this is a sign saying to the body you’re exposed to some microbes that are making you sick, alerting the immune system of the danger.

We have two types of immunity, innate, and adaptive.

  1. Innate Immunity – This is an immunity we are born with from the get-go to defend ourselves against any invaders. It is the first line of defense which is mainly produced by the gut.
  2. Adaptive Immunity  Also known as acquired immunity as you can guess from the name, this develops as we go through life either by getting sick or through vaccines.  Our immune system gets stronger by fighting different diseases or bugs as a result we build antibodies that remember previous pathogens.

What Foods Are Best For A Healthy Gut and Immune System?

What we feed our gut determines the ability of a healthy strong environment and a diverse microbial population that can bring about a healthy immune system.  A healthy microbiota can defend us from all kinds of diseases. On the other hand, poor diet choices will cause gut inflammation which makes us vulnerable to infections.

Diet and lifestyle play a big role in the health and well-being of an individual. Here are some of the best dietary choices to consider when making a good gut diet for diverse microbes to flourish.

Eating large amounts of plants.  Dr. Heber who is a professor,  emeritus of medicine at UCLA Health recommends eating a variety of plants, seven servings of different colors of fruits and vegetables. ” If you want to be on the healthy side plant-based diet is a way to go,” he says. He also said, ” Nutrition is a key modulator of the immune system”.

Eating healthy fats.  Good fats support the immune system, he suggested cooking with Olive and Avacado oil

Eating wild-caught fish.  It is best to eat wild-caught fish than farm fish. Wild fish are not fed antibiotics. if you are not a fish fan, taking fish oil supplements might be an option.

Eating enough protein.  Eating a good source of protein from grass-fed animals and plants help muscle growth and overall


Prebiotics and probiotics-rich foods.  Examples of prebiotic foods that have high fiber are – garlic, onion. asparagus, green plantains. Probiotics are fermented foods like Kimchi, Kefir, Miso, Sauerkraut, and yogurt. These are excellent foods that are helping to multiply good gut bacteria and create a healthy gastrointestinal tract.

How Your Gut Regulates Your Immune Systems

The gut is the gatekeeper that regulates the immune system to activate an immune response that triggers a defense mechanism against any invaders.   The microbiome stops the entry of any disease-causing organisms into the bloodstream or to the other organs.  Our immune system is always ready to come to our rescue from any invaders coming our way to attack. It recognizes between friendly microbes and harmful ones and therefore acts accordingly.

Since the gut is the first line of defense it communicates with immune cells and trains them to identify dangerous and foreign pathogens from the friendly microbes. This prepares the immune system from over-reacting, to have balance, and prevent from attacking itself which is known as autoimmune.  The diverse microbes in the gut and the immune cell interact with each other to have a mutual relationship.
In a nutshell, the immune system and the gut are interconnected and one can’t function without the other thus they support each other to promote a healthy body.


A healthy gut equals a healthy immune system, they go hand in hand. Therefore having a healthy gut is the key to having an optimal functioning immune system. You’ll find that you’re no longer vulnerable to getting the common cold easily and even you can fight the flu with no problem because of having a strong immune system. A strong and full-functioning immune system will always depend on a diverse gut microbiome, so what you feed the gut is what will protect you from many diseases.

What you put in your mouth matters. Without eating different, whole foods, for instance, colorful vegetables, fruits,  complex carbohydrates, and avoiding sugar, alcohol, refined carbohydrates the gut will be damaged and the immune system will not be able to protect or defend us from harmful microorganisms.


  1. https://www.ufjf.br/imunologia/files/2009/05/Flavia-Role-of-the-gut-microbiota-in.pdf
  2. https://pubmed.ncbi.nlm.nih.gov/28095889/
  3. https://pubmed.ncbi.nlm.nih.gov/24848255/
  4. https://pubmed.ncbi.nlm.nih.gov/31315227/
  5. https://www.webmd.com/digestive-disorders/what-your-gut-bacteria-say-your-health
  6. To boost immunity, look to the gut – Vital Signs – UCLA Health – Los Angeles, CA

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