The Gut Immune Axis

The research on the effect that the gut has on immunity is undeniable, with scientists associating the quality of our immune systems to the quality of beneficial bacteria we store in the microbiome.   This intricate connection between your gut microbiome and your immune system is truly fascinating and eye opening to get to understand, so we can begin to support a healthy gut-immune connection.

Among its many roles, the gut microbiome is crucial to the development and functioning of our immune system. This relationship is best understood when the get to know the foundational basics of the immune system and how it operates.

How The Immune System Operates

The immune system is a vast network of cells, proteins and organs that fight harmful substances which come into contact within the body. This could be in the form of pathogenic bacteria or disease causing changes that occur like a damaged cell. The immune system is them activated by an alert that signals a substance that the body doesn’t recognise as its own (an antigen). When we have an established immune system that is operating optimally, the immune system recognises, identifies and neutralises antigens. This process mostly goes completely unnoticed by us. When the immune system is unable to fend off these certain antigen threats, we can get sick.

How The Gut Is Connected To The Immune System

The gut and immune system are connected through various pathways, these collected are known as the gut-immune axis. Our gut microbes are the key component of this connection and impact the immune system directly.

The Immune System Setting The Foundation 

Even before we were born, microbes help set the foundation. The immune system then learns how to distinguish between benign substances and pathogenic antigens. From there, as we grow and adapt through life, this relationship between the gut microbiome and the immune system, continues to evolve and fine tune its response pathways.

The Gut Microbes Purpose

Gut microbes protect you from external threats through various mechanisms. For example, several lactic acid bacteria in the gut produce antimicrobial substances called bacteriocins that inhibit or kill pathogenic bacteria such as Salmonella. Other microbes produce metabolic products known as metabolites that can facilitate communication between gut cells and immune cells.

How To Support The Gut-Immune Connection

While certain factors like age and genetics are fixed, diet, exercise, sleep quality, stress, and environmental exposures can all shape the structure and function of the microbiome throughout life. 

Here are four science-derived strategies to foster a healthy gut-immune connection: 

• Increase your daily fibre intake. In the digestive tract, certain fibres are fermented by gut microbes and biotransformed into short-chain fatty acids (SCFAs), which have a range of benefits in the body, including the maintenance of immune health. This includes SCFAs, that interact with immune cells and regulate anti-inflammatory and antioxidant responses to assist in defending the immune system against pathogens and certain autoimmune conditions.
• Make sure to prioritise good quality sleep. Your body operates on a 24-hour cycle, known as your circadian rhythm, this plays a key role in maintaining homeostasis of the microbiome. Emerging data also shows that the gut microbiome has its own circadian clock, exhibiting daily shifts in its composition. Changes to your normal “rhythms” induce what is known as “circadian misalignment”, which may disrupt your microbes and therefore, the important functions they perform.
• Make managing stress a priority. The inflammation that often accompanies high levels of stress triggers blooms of pathogenic microbes that promote dysbiosis and increased intestinal permeability (aka leaky gut). 
• Incorporate a probiotic. Specific strains of probiotics have been studied to support a range of benefits within the gastrointestinal system, including the reinforcement of gut-barrier function and the support the communication between gut and immune cells. 

Inside the Gut 

Your gut is quite literally your intestines, although the word is frequently used for any part of your digestive system, especially your stomach. This includes our four-layered (mucosa, submucosa, muscularis mucosa, and serosa) organisation of the digestive tract. The length of the small and large intestines is at least 15 ft in length. The small intestine can measure about 9–16 ft, while the large intestine is roughly 5 ft long. The normal thickness of the small intestinal wall is 3–5 mm, and 1–5 mm in the large intestine. This is known as our gut lining or gut wall.

The immune system co-evolves with our microorganisms. When we learn to collaborate with the microbes living in and around us. This intrinsic connection between the gut and the immune system contributes to immune homeostasis, immune responses, and protection against pathogen establishment. This is why, modern living can be counter helpful towards the immune system, with things such as; antibiotics, westernised diets, environmental toxins, lack of exposure to nature and high stress levels. This aspects have disrupted our relationship with microbes, giving rise to immune diseases and disorders that are linked to the health of our microbiome. As we incorporate ways to prevent, remediate, and even eradicate these issues, the microbiome holds the potential to validate new solutions and revolutionise how we think about our health.