How Gut Bacteria Helps the Immune System

Whenever we think of our gut, we usually associate it with eating and eliminating wastes from the body. However, growing research shows that there’s more to it than processing food and passing stool.  Now, scientists are discovering that 70% to 80% of our immune system is housed in the digestive tract. Didn’t think our gut could do more than absorb nutrients, eh?

Well, there’s more to the gut as being part of the digestive process. It’s also included in the body’s fight against diseases. The digestive tract is an essential component of our immune system. It’s primarily responsible for keeping out unwanted microorganisms and developing antibodies against diseases.

The lining in our intestines serves as a barrier to block harmful substances and prevent them from entering the body. Cells along the gut trap, neutralize, and expel harmful microorganisms from the body. In case these pathogens still go through, intestinal walls sense their presence and alert immune cells to eliminate invaders.

Aside from acting as border control against bacteria, fungi, and viruses, the gut is also home to a host of immune cells known as gut-associated lymphoid tissue (GALT). These immune cells in the digestive tract communicate with other parts of the immune system to ensure that defenses are intact. GALT, various organs, cells, and proteins all work together to keep the body healthy and strong against diseases.

Living and working alongside GALT are good bacteria. They form a close and mutual relationship with immune cells that their presence and growth can help a person become strong and healthy.

How Gut Bacteria Help the Immune System

Our gut is also home to beneficial bacteria that affect several body functions, including immunity and metabolism. These bacteria’s presence develops early in life, and their balance is mainly determined by age, diet, medication, stress, and illness. Gut bacteria can thrive or decrease based on the interplay of the factors mentioned.

How Does Gut Bacteria Help the Immune System

Recent technologies, such as My Psomagen and other gut microbiome tests, also provide insight into the diversity of gut bacteria and the digestive tract’s overall condition. Inherent factors and new ways of looking into gut health can help people understand the relationship between gut bacteria and the immune system.

The diversity of good bacteria is key to a resilient immune system. They produce fatty acids and other compounds that boost the immune cells that live alongside them in the gut. When good bacteria abound, immunity is increased, and it can continue its function of keeping pathogens and illnesses at bay.

Thus, it is essential to ensure that good bacteria proliferate in the gut. Good bacteria contribute to the growth of gut immune cells. In turn, immune cells also protect good bacteria by defending them from invaders.

Mutual Relationship Between Gut Bacteria and Immune System

In contrast, when an imbalance of bad bacteria overcome the gut, harmful microorganisms escape the intestinal lining and make their way to the bloodstream. Immune cells then focus on eliminating these intruders, leaving the body exposed to risks of certain diseases.

This mutual relationship is demonstrated in a study in which introducing types of good bacteria leads to increased immune cells called neutrophils. Higher concentrations of the immune cells led to faster recovery of patients who underwent bone marrow transplants for blood cancer.

Nourishing Good Bacteria for Improved Immunity

Given the cooperation between good bacteria and immune cells in the gut, keeping both of them in good shape is essential.

One way to do this is to ‘feed’ good bacteria with suitable types of food and drinks to thrive. This includes fiber-enriched foods that good bacteria break down into fatty acids and essential compounds to fuel disease-fighting cells’ growth. Fermented foods are also amenable sources that add to existing good bacteria in the gut.

Other ways of nourishing the gut include frequent exercise to keep the body active. Reducing stress also helps good bacteria flourish, while managing antibiotic intake can ensure its balance. The homeostasis of good bacteria helps strengthen immune cells as they carry out fighting pathogens and illnesses.


Our gut does more than absorbing nutrients from food and eliminating wastes. It is a powerhouse of both immune cells and good bacteria that interact and cooperate to ensure a strong line of defense against harmful bacteria, viruses, fungi, and toxins.

Good bacteria in the gut nourish immune cells by producing essential compounds that fuel their growth. When immune cells are abundant, it results in a resilient immune system that fights off invaders as they appear and prepares the body to counter various illnesses.