Relationship Between Gut and Immunity

Introduction

Your body contains trillions of microbes that live in harmony with the immune system. The interaction of gut microbiomes such as bacteria, viruses, protozoa, and fungi plays a key role in developing a normal gut and the systematic functioning of the immune system. However, any imbalance or disturbance in the relationship between the gut microbiome and the immune system results in several gastrointestinal disorders and immune-mediated diseases. 

Do you know?

About 70% of your immune system resides in the gut. A well-balanced microbiota plays a major role in driving off harmful substances, including viruses and bacteria, and allowing your immune system to function properly. 

Now, let’s look at things that can hamper your immune system. 

A poor diet	A diet that lacks fibre and essential nutrients is called a poor diet. It can stop your immune system from functioning properly.	A poor diet can also cause an imbalance in your gut microbiota.
An unhealthy lifestyle	A lifestyle that lacks exercise and includes poor diet choices, smoking, and excessive drinking is an unhealthy lifestyle.	An unhealthy lifestyle can affect the immune system and increase the risk of severe infectious diseases.
A lack of sleep	Studies reveal that not getting enough or quality sleep can affect one’s immune system.	A lack of sleep due to an unhealthy lifestyle and poor eating habits can make you sick, causing you to produce fewer antibodies to eliminate infection.
Medications	Certain medications can weaken your immune system.	Prolonged use of medications, including immunosuppressants, corticosteroids, and chemotherapy treatments, can weaken or overstimulate the immune response.
Chronic Stress	Chronic stress is unhealthy, and it can weaken your immune system.	Chronic stress can increase your cortisol level in the blood, causing too much inflammation, fatigue, acne, and weight gain.

Also read: https://redcliffelabs.com/myhealth/health/nourish-your-guts-best-foods-for-gut-health/

The relationship between the gut and the immune system is deep and has many different aspects. Let’s discuss them in detail. 

• Gut-Associated Lymphoid Tissue (GALT)

It contains a collection of multifollicular structures. It works in the immune system to safeguard the body from invasion in the gut. 

Structure: GALT is a critical component of the mucosal immune system. It includes isolated lymphoid follicles, appendix, and Peyer’s patches. 

Function: GALT initiates immune responses to pathogens while maintaining resistance to dietary antigens and commensal bacteria. 

• Microbiome

It is the totality of microorganisms such as bacteria, fungi, protozoa, and viruses and their collective genetic material in the gastrointestinal tract (GT). 

Diversity and Composition: Your gut microbiome consists of millions of microorganisms affecting the immune system. A diverse microbiome functions much better than a microbiome and is responsible for a strong and healthy immune system. 

Immunity Development: Early-life microbiota exposure helps develop a healthy immune system. 

• Immune Cells

These cells develop from stem cells in the bone marrow and become white blood cells. 

Interaction: The immune system interacts with the microbiome, which likewise conditions the intrinsic insusceptible framework by means of preserved molecular patterns that are straightforwardly perceived by pattern recognition receptors. 

Regulation: Interactions such as macrophages, dendritic cells, T cells, and B cells help regulate immune responses, promoting tolerance to harmless antigens and mounting responses against pathogens. 

• Gut Barrier Function

It provides a permeable barrier to the gut for absorbing nutrients and defense from external factors. 

Gut Epithelial Cells: The gut epithelial cells maintain the healthy relationship between the gut microbiota and the immune system. They form a barrier that stops pathogens from invading while allowing nutrients to be absorbed. 

Mucus Layer: The mucous layer is presented by goblet cells. It consists of antimicrobial pathogens that neutralize harmful substances. 

• Immune Responses 

The immune system recognizes the antigens on the surface of substances, such as bacteria or viruses, and attacks and destroys them. 

Innate Immunity: The gut microbiota that lives in the gastrointestinal (GI) tract provides essential health benefits to host immunity by regulating immune homeostasis. Besides, the gut is important in inducing antimicrobial peptide expression against pathogens.

Adaptive Immunity: The gut presents antigens to T and B cells, resulting in the production of specific antibodies, particularly IgA, and thus playing a key role in mucosal immunity. 

• Dysbiosis and disease

Dysbiosis is defined as a change in the composition of the intestinal microbiota. It is linked to the pathogenesis of both intestinal and extraintestinal disorders. The intestinal disorders include inflammatory bowel disease and coeliac disease. At the same time, extra-intestinal disorders include metabolic syndrome, cardiovascular disease, and allergies. 

Dysbiosis: The gut microbiome imbalance results in irritable bowel syndrome (IBS), allergies, and autoimmune conditions. 

Inflammation: Chronic inflammation in the gut can result in chronic hepatic and renal disease, malignancy, and obesity. 

• Nutritional Influence

Whatever we eat influences our health in positive and negative ways. Nutritionally dense food encourages the growth of good bacteria. A healthy diet nourishes the brain and protects it from oxidative stress. 

Diet: It deeply affects your gut microbiome and, thus, your immune system. Foods that are rich in fiber promote the growth of beneficial bacteria. However, a diet with a deficiency or excess of nutrients that can hamper your health can lead to dysbiosis. 

Probiotics and prebiotics promote the growth of beneficial microbes and enhance immune function, thereby supporting gut health. 

• Gut-Brain Axis

It is a biochemical signaling process between the GI tract and the central nervous system (CNS). 

Communication: It involves communication between the gut and the brain through the gut-brain axis, involving hormones, the nervous system, and immune signaling. 

Impact on Immunity: It is common knowledge that stress and other psychological factors influence gut health and immune function. 

Also read: 

https://redcliffelabs.com/myhealth/health/guarding-your-health-exploring-the-need-for-an-immunity-test/ 

Final Views: 

The gut and the immune system are connected through structural, molecular, and cellular interactions. A healthy gut microbiome includes beneficial bacteria and is vital for a healthy immune system. The gut's health is important for proper immune system functioning, and a healthy gut microbiome contributes to overall immune health.