How Are Our Gut Health And The Immune System Connected?

“You are what you eat” could not get any truer. Did you know your gut makes up most of your immunity? Your gut microbiome, made up of trillions of microbes, plays a crucial role in your immune system - in fact, 70% of your immune system is in your gut. These bacteria protect you from harmful invaders, provide nutrients, and help with blood sugar regulation. However, when your microbiome is imbalanced, you can lose your gut lymphatic layer, resulting in decreased immune function and an increased risk of autoimmune disease. T cells in your immune system not only differentiate between your own cells and pathogens but also suppress inflammation, and a lack of microbiomes can lead to less production of small-chain fatty acids like butyrate, which helps balance blood sugars and improve immune function. 

Consequently, doctors often prioritise examining the gastrointestinal tract when a patient is experiencing recurrent health issues or prolonged discomforts. Curious to know more about the link between the gut and the immune system? Let us enlighten you with the very same thing in the space ahead.

Root causes of poor gut health

As previously mentioned, the gut contains a diverse array of microorganisms, and each person's gut microbiome is distinct and influenced by their lifestyle and dietary habits. Consequently, impaired gut health is typically a gradual process, resulting from a combination of various factors. Therefore, when attempting to comprehend and treat a compromised gut, the following are some crucial considerations to explore first.

Diet history of highly processed foods

The food we consume influences our bodies, such as the functions of hormones, neurotransmitters and metabolism. If our current or past diet mainly consists of highly processed foods and refined sugar, it can have a profound impact on our gut health and microbiome, paving the way for the growth of harmful bacteria. Additionally, a nutrient-deficient diet lacking essential vitamins, minerals, and other immune-boosting compounds can also weaken our immunity.

Long-term stress

“Stress gets the best of you” is a common saying and holds true. When you have stressed your entire body is under a threat including your gut. Research shows that ongoing stress impacts gut health such as  gastric secretion, gut motility, mucosal permeability and barrier function, all of which are extremely important for proper gut function. In fact, the gut microbiota seems to respond to stress signals from the body directly, indicating that long-term, high levels of stress hormones like cortisol can contribute to a heightened inflammatory response in the gut.

Overuse of Antibiotics and NSAIDS

Prolonged use of antibiotics can have a detrimental effect on the beneficial bacteria in our gut  and impair its functions. Similarly, excessive use of anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin can damage the intestinal lining and lead to an increase in permeability, deteriorating the gut health.

Imbalances in blood sugar levels

Fluctuations in blood sugar levels, resulting from a diet high in refined carbohydrates and sugar, can lead to increased gut permeability. The gut has 7 protective layers, which get corroded due to a disturbance in the microbiome, leading to increased permeability. Studies suggest that there is a direct relationship between blood sugar and gut health, with alterations in intestinal bacteria potentially impacting sugar and fat metabolism, thereby contributing to elevated blood sugar levels.

Opportunistic microbes

Not all microbes are your best friend. Sometimes, when your immunity is compromised, the good bacteria may turn opportunistic. Therefore, ongoing gut discomforts might also point to an underlying issue, such as a fungal overgrowth, parasite, or other infection. Speak with your doctor about appropriate testing to rule out these possibilities.

The connection between the gut and immunity

The gastrointestinal tract, especially the small and large intestines, houses a specialized layer of tissue called gut-associated lymphatic tissue (GALT). This tissue is composed of various immune cells, including lymphocytes, plasma cells, macrophages, and dendritic cells, which are strategically positioned to safeguard against harmful pathogens and antigens that enter the body through the digestive system.

By recognizing and responding to foreign substances, such as bacteria, viruses, and parasites, that enter the gut, the GALT plays a vital role in protecting the body from infections and diseases. It also regulates immune responses to food and other substances consumed, preventing unnecessary inflammation and allergic reactions.

Overall, gut-associated lymphatic tissue is a crucial component of the immune system, playing an essential role in maintaining a healthy gut and preventing infections and diseases that can arise from a compromised gut barrier.

The most effective way to prevent the growth of pathogenic or harmful microbes is to have a diverse gut microbiome. A plentiful supply of "good" bacteria makes it less likely for harmful bacteria to propagate and trigger an immune response. If harmful bacteria do surpass a certain threshold, the immune system is activated to produce cytokines, which are vital messengers that coordinate and regulate the immune system's inflammatory response.

An escalated inflammatory response in the gut can lead to damage to the intestinal lining and increased permeability, commonly known as leaky gut. The intestinal wall has "tight junctions" that function to permit the passage of nutrients and water. When these junctions are damaged, toxins and other harmful substances seep through the intestinal wall and into the bloodstream, prompting an immune response.

Imbalances in the gut microbiome have been associated with various health challenges, including difficulties with reaching or maintaining a healthy weight, severe blood sugar dysregulation, blood pressure issues, and other serious problems.

How to address gut health for better immunity

Here are some strategies you can use for better and a healthy gut as well as immunity:

1. Limiting sugar and refined carbohydrates: while we all relish sweets and fast foods, it is better to restrict them for a while and have them occasionally. Foods like white bread, pasta, cookies, and cakes should be avoided or limited to support gut and immune health. A high-sugar diet can contribute to fungal proliferation and intestinal permeability in the gut.
2. Eating a wide variety of plant foods: the more colourful your platter looks, the better! Consuming a variety of fruits and vegetables provides a nutrient and antioxidant-rich diet and plenty of gut-supportive fibre.
3. Consuming probiotics and prebiotics: Probiotic-rich foods like raw sauerkraut and kimchi, miso, kombucha tea, and kefir can help support gut health. Prebiotics, which are non-digestible carbohydrates, are naturally present in many high-fibre foods, particularly onions, garlic, asparagus, green bananas, green plantains, and Jerusalem artichokes.
4. Stress management: the benefits of a stress-free life go without mentioning. Studies have shown the intimate connection between stress and gut health and the positive impacts of practices like meditation. 

Wanna know more about your gut health? You can get detailed information about your gut health and personalised insights with Decode Age’s Gut microbiome test.

Conclusion/summary:

The gut and the immune system have a close relationship, with the gut microbiome playing a crucial role in maintaining a healthy immune system. An imbalanced microbiome can lead to compromised immunity, which increases the risk of autoimmune diseases. Poor gut health can result from a combination of factors, including an unhealthy diet, long-term stress, overuse of antibiotics, NSAIDs, blood sugar imbalances, and gut pathogens. 

The gut-associated lymphatic tissue is a vital component of the immune system, safeguarding against harmful pathogens, regulating immune responses, and preventing unnecessary inflammation and allergic reactions. Maintaining a diverse gut microbiome is essential for preventing the growth of pathogenic or harmful microbes and supporting a healthy immune system. Therefore, it is crucial to prioritize gut health, and if necessary, seek advice from healthcare providers and explore options like gut health testing at home to maintain optimal gut health.