Gut Health and Your Immune System
When you imagine your immune system, you probably think of white blood cells racing around your body to seek out and destroy invaders such as bacteria, viruses and other nasties. It may come as a surprise to learn over three quarters of your immune system is located in your gut.
Far from simply concerning itself simply with obtaining nutrients from food and expelling waste products, your gut has a major influence on your immune health. In this article we’ll discover more about this fascinating relationship.
Your microbiome is the name given to the complex community of bacteria found in your gut, primarily in your large intestine or colon. Living in an area roughly five feet in length, your microbiome contains many more bacteria than you have cells in your body, belonging to over 2000 different species.
The bacteria in your microbiome have evolved to live in symbiosis with you, their host. Even though the majority of the time you’re probably not aware of their existence, they have a profound impact on your health and wellbeing. This has earned these symbiotic bacteria the nickname of ‘friendly bacteria’.
Your microbiome is able to influence your health in diverse ways because the bacteria living within it produce chemical messengers. These are sent all over the body. These chemicals vary depending which types of bacteria are in charge, with each messenger having different effects on health.
Things don’t always go well in the microbiome. Certain types of bacteria, known as ‘unfriendly bacteria’, can sometimes take over. Normally, the friendly bacteria keep the unfriendly bacteria from reproducing, but if they start to gain the upper hand, a situation known as dysbiosis occurs. Unfriendly bacteria produce harmful chemical messengers, hindering immune system function, and damage the intestinal lining causing digestive issues and impeding nutrient absorption.
The types and proportions of bacteria living in the gut vary widely from person to person. Many factors impact upon the makeup of the microbiome, from food to stress levels, environmental toxins, antibiotic use and even your genes.
Your Microbiome and Your Immune System
Science is only beginning to understand the many ways gut bacteria interact with the immune system. It makes sense for your microbiome to have a close relationship with your immune system because many pathogens enter the body through the mouth and make their way to the gut.
The bacteria in your microbiome influence your immune system both directly and indirectly.
Friendly bacteria can directly discourage or kill invaders and compete with undesirable microbes for space and food. They also keep the digestive lining healthy by maintaining its protective outer layer, helping to prevent pathogens latching on and gaining access to the body.
On the other hand, friendly bacteria and immune cells communicate with each other in a two-way process. Your microbiome can help educate your immune system to distinguish between friend and foe, as well as influence the types of white blood cells produced and how quickly they mature. Bacteria in the microbiome also release substances which control inflammation.
The microbiome has a major influence on the sensitivity of the immune system. We don’t want the immune system to be ineffective at detecting and reacting to invaders, but on the other hand, problems can occur if it becomes overactive and loses its selectivity. An immune system which cannot distinguish between friend and foe may attack harmless body cells, leading to autoimmune diseases such as rheumatoid arthritis and SLE, as well as allergies to innocuous substances.
Your immune system won’t be in good shape if your gut isn’t working well. If you find you’re picking up every bug going, or you suffer from allergies or autoimmune issues, one culprit could be your gut health.
Encouraging a Healthy Microbiome
Bacteria need food to survive, and friendly bacteria thrive on fibre, while unfriendly bacteria love sugar. If you feed your beneficial bacteria the food they need by eating plenty of plant-based foods, they will have a chance to thrive. At the same time, it’s a good idea to avoid foods which encourage unfriendly bacteria.
The bacteria also need a healthy environment in the gut to be able to establish themselves and reproduce.
Functional Medicine and Your Gut
Functional Medicine Practitioners place good gut health at the heart of their therapeutic approach because establishing a healthy digestive system is crucial for your overall health.
Functional testing can provide valuable insight into how your gut is working. By examining the types of bacteria in your stool, along with the chemicals they produce, a picture can be built of the functioning of your digestive system. This will help to pinpoint what is going wrong and highlight where you personally need support.