Gut & Immune System: Understanding a Symbiotic Relationship

by Samit Patel on September 01, 2021

Bacteria are known to assist the digestion of certain foods. Thanks to medical advances, it was discovered that bacterial cells in the body are as many as human cells. In fact, there are over ten thousand species of bacterial cells present in the gut known as the gut microbiota. Their sheer number is enough to make you realise just how important they are to your body’s processes.

What Is the Gut Microbiota?

The gut microbiota refers to the hundred trillion microbial cells housed in the human gut. Surprisingly, they are 150 times larger and ten times the number of human cells. Most of them are found along the gastrointestinal tract and the skin, particularly in the nose, genitals, mouth, nose, and ears. They are also located on every surface the skin comes in contact with.

How Do Gut Bacteria Affect the Immune System? 

Before determining the relationship between gut bacteria and the immune system, it’s important to know how this system works. It comprises cells, organs, and proteins that protect the body from foreign invaders, including germs, viruses, fungi, and pathogens. Its first line of defence is the immune cells that identify and neutralise harmful pathogenic or environmental substances. 

The immune system is made up of innate and adaptive immune systems. The innate immune system protects the body against non-specific pathogens through killer cells and phagocytes. On the other hand, the adaptive immune system learns to defend the body over time by targeting pathogens already present in the body and adapting to changes in their strains.

The immune system is interconnected with gut bacteria. Microbial units and human cells also formed symbiotic relationships by introducing prokaryotic cells into eukaryotic cells. This developed into a holobiont, which is an ecosystem with a host closely associated and has complex interactions with other species.

What Are Ways to Improve Gut Health?

Healthy bac­te­ria in the gut are responsible for distinguishing healthy cells and tissues from potentially harmful ones through the development of T-cells. When there is an overgrowth of bad bacteria, the immune system can start attacking even the healthy cells. As a result, the body becomes prone to sickness and has a harder time recovering.

Because of this, maintaining the balance of the digestive system is important. Having a wide variety of good gut bacteria can also boost immune system function. Other potential health benefits include combating obesity and easing depression symptoms. 

To boost immunity, practice healthy habits that keep your digestive system functioning properly. Start watching what you eat and being mindful of your diet. Since your gut needs a healthy dose of probiotics, add fermented foods to your diet. Kimchi, miso, tempeh, and kombucha have live cultures that break down foods and improve the immune system.


The human gut is more complex than you might think. Besides effective digestion, it has a huge impact on the immune system and overall health. For this reason, it’s vital to adopt healthy habits and make necessary lifestyle changes to improve gut health. Aside from the suggestions in this guide, another way to take better care of your gut is to head to a health and wellness clinic for coeliac testing.

If you are wondering how to improve gut health, reaching out to our wellness clinic may be the answer. At Unichem Greenhithe Pharmacy, we offer coeliac testing to determine if you have coeliac disease. Book an appointment today!