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The Relationship Between Gut Health and Immunity

Gut Health
Longevity By Nature

Almost constantly, patients ask, “How do I improve my immune system?” To put it simply, you can’t have good immunity with poor gut health. The two are very closely linked, which means if one of these is not functioning properly, it will cause problems in the other. The digestive system contains more than 70 percent of the body’s immune system, meaning a large majority of the immune system resides in the gut. The gut microbiota plays a critical role when it comes to our health. Bacteria and other microorganisms within the gut communicate directly with the immune system. So, when you have dysfunction in your gut, it will negatively impact your immune system. If you are hoping to improve your immune system, your gut may play a large part in doing so.

The gut microbiome consists of bacteria, fungi, viruses and other microbes. Your gut is home to thousands of species of microorganisms and having diverse bacteria in your gut leads to optimal health. Since the organisms living in your gut consist of good and bad bacteria, levels can easily sway the wrong direction if you don’t take good care of your gut health. Ensuring that you are providing a quality microbiome is essential when it comes to a healthy gut and a healthy immune system. Maintaining a balanced diet and practicing healthy habits will promote the growth of healthy microbiota.

If your digestive system becomes damaged, you are at risk for dysbiosis. This occurs when you have an inadequate or imbalanced microbiome. Dysbiosis may lead to increased gut permeability, also known as leaky gut. The protective barrier inside your digestive system is supposed to control what is allowed into your bloodstream. When this barrier isn’t as tight as it should be, it can let unwanted substances through. Recent studies indicate that dysbiosis and gut permeability are associated with gastrointestinal disorders, autoimmune disorders and metabolic disorders such as irritable bowel syndrome (IBS), lupus and type II diabetes, respectively.

What Can Damage Gut Health?

Your diet contributes significantly to your gut health. Processed foods and the standard American diet can be very detrimental to the health of your digestive system. Diets high in packaged foods, refined sugars and grains, too much red meat, high sugar drinks and high fructose corn syrup all put you at risk for decreased immunity. Additionally, other environmental factors significantly affect human gut microbiota, which in turn can impact overall health.

A variety of other factors can lead to poor gut health:

• Overuse of antibiotics
• Overuse of non-steroidal anti-inflammatory drugs (NSAIDs)
• Too much alcohol
• Exposure to heavy metals and pesticides

If your diet isn’t as healthy as it should be, then your immune system won’t function as well.

There are several non-dietary lifestyle factors that can heavily impact gut microbiota. Smoking, lack of exercise, stress, poor sleeping habits and more can all have negative effects on overall gut health. These types of factors tend to be overlooked in relation to the digestive system, but it’s important to note that there are lifestyle habits, choices and events that can directly impact our gut health and overall immunity.

Instead of trying to stop the unhealthy diet habits and lifestyle choices, many people want a quick fix. Some end up taking multivitamins while continuing to eat poorly and live an overall unhealthy lifestyle. It’s important to make the necessary dietary and lifestyle changes, while supplementing with additional vitamins and minerals if needed. It’s common to be deficient in several nutrients, so check with your medical provider to ensure your levels of vitamin C, vitamin D, zinc, selenium and iron are all adequate. This will help boost immunity. If you are significantly deficient in certain vitamins or minerals, you may need to supplement temporarily to restore proper levels, but this is not always a good long-term fix. The best way to absorb these nutrients is through our food intake. However, even with supplementation, it is possible that you won’t process those nutrients correctly if the gut isn’t healthy.

How Can One Improve Gut Health?

Improving gut health relies heavily on your diet. The first step is to decrease intake of inflammatory foods. Processed sugar and refined grains are examples of foods that can damage your gut. Fried foods, sugar sweetened beverages, red meat and alcohol should also be limited.

The next step is to increase consumption of prebiotics. These are foods that are high in fiber and work to feed the healthy microbiome in your gut. Increasing the variety of colorful fruits and vegetables you eat can help tremendously. The best food options are produce that is fresh, in season and locally grown because fruits and vegetables lose their nutrients over time. Frozen produce often has a good supply of nutrients because they are packaged at the peak of ripeness, but they can lose nutritional value if stored too long. Changing your diet to a greater variety of healthy foods can influence your microbial profiles.

Another helpful change is to increase your consumption of probiotics to modify your microbial populations. Probiotics can be found in foods with live cultures such as yogurt, kefir, kombucha or sauerkraut. These foods contain live bacteria to increase the population of good microbiomes in your digestive system. While live bacteria are the most beneficial to your gut, probiotic supplements have also been shown in studies to be effective in improving gut health.

Adding protein-rich foods to your diet will help maintain gut health. Foods such as wild caught fish, white meat chicken and lentils can provide you with high levels of protein without increasing inflammation.

Gut Health in Children

A healthy microbiome is not only important in adult health, but in children as well. There may be life-long consequences to the immune system when it comes to infant nutrition. Developing a strong gut microbiota is important and is linked to the development of the immune system. An infant acquires their initial gut microbiome from their mother. If the mother’s microbiome isn’t healthy, she cannot contribute a quality microbiome to her child. Beginning healthy habits early is beneficial to one’s health throughout life.

Fixing a Damaged Gut

Sometimes, the digestive system is too damaged to tolerate inflammatory foods at all. These patients will often develop food sensitivities due to the ongoing dysbiosis and increased gut permeability. Blood tests for immunoglobulins may be used to determine if there is a food allergy, but often people will have food sensitivities that won’t show up on their blood work. Keeping a food diary may be recommended to connect symptoms with dietary choices. This can greatly help patients trace back to what may be negatively affecting their gut health.

Patients may then utilize an elimination diet under their health practitioner’s supervision. For a minimum of 21 days, the patient will eliminate many inflammatory foods at once including beef, pork, dairy, eggs, soy, corn, wheat, sugar, peanuts, alcohol and caffeine. In many cases, those three weeks allows the gut to heal and function optimally again, but some patients with more severe dysfunction may need longer to heal. After the 21 days, the patient will begin to slowly reintroduce inflammatory foods to see which ones cause a response. If a food causes a response, the patient may need to eliminate that food for a longer period of time.

Oftentimes, a patient may be able to eat those trigger foods without issue after the brief elimination. This is important because moderate consumption of meat, dairy and eggs are often quality sources of nutrients when the gut is healthy. Patients should continue to eat a variety of fruits and vegetables and only consume those inflammatory foods in moderation to maintain their gut health and good microbiome. The food diary can also indicate when nutritional supplements are necessary to help correct a deficiency in the diet. Ideally, supplements should only be needed temporarily, and the patient should work to increase those nutrients in their diet whenever possible.

The relationship between the gut health and overall immune function is continuing to be researched. Studies are cataloging the types of gut bacteria present in patients with many chronic diseases, autoimmune disorders and even cancers. Chronic inflammation is associated with disease and can be mitigated by making dietary changes. Taking small steps to improve your diet can create big changes in your digestive health and immune system.

Dr. Amy Koch earned a BS in biology from Truman State University in 2001 and graduated from Logan University’s DC program in 2004. Dr. Koch is currently working as a faculty clinician overseeing students in the Viscero-somatic rotation. Dr. Koch is certified in acupuncture and has been a faculty member at Logan University since 2015. She is an assistant professor and serves as the faculty senate treasurer.