Leaky gut, autoimmunity, and mental health – What are the links? Part 2

Leaky gut, allergies, and autoimmunity

Allergies and autoimmunity are directly linked to our immune system. They result when our immune system works a bit too hard – when our immune cells become a little too active.

Allergies occur when our immune system is activated to fight things that are not harmful, like certain foods, pollen, or pet dander. The body thinks they’re dangerous invaders that must be fought, and sends out immune cells that cause inflammation to try and eliminate the allergen.

Autoimmunity, on the other hand, is when our immune system is activated to fight our own cells and tissues. The immune system becomes “intolerant to self.” For example, Hashimoto’s (an autoimmune disease) occurs when our immune system fights the tissue cells of our thyroid. After continued inflammation, enough of these cells die and the function of the thyroid starts to weaken, producing less and less thyroid hormone, which is essential for the body as it is found in every single cell of the body.

Many things can contribute to autoimmunity, and leaky gut may be a bigger factor than we once thought. This is because of the impact of allowing undigested food, bacteria, etc. enter our bodies and how our immune system tries to fight them. A large part of our immune system is located just on the other side of that one-cell thick layer of enterocytes.

When our bodies detect things in our internal circulation that don’t belong (like undigested food or bacteria) our immune system kicks in. This immune response to things that “leaked” into our bodies can cause the release of even more inflammatory compounds this time inside our bodies and bloodstreams (i.e. on the other side of the first layer of enterocytes). The allergic and inflammatory responses that happen around our guts may affect the gut directly. But, once these are absorbed into the bloodstream, they can affect other parts of the body, too.

This is the connection we see between leaky gut, allergies, and autoimmunity. It’s not just the leaky gut, it’s the interactions between what leaks into our bodies and our immune system’s response to them.

Having a healthy gut microbiota plays an important role in how our immune systems mature from when we were infants. Dysbiosis in our gut at an early age can promote changes in our immune response, and increase the risk of allergic and autoimmune diseases.

It seems that gut dysbiosis and “leaky gut” might be part of the chain of reactions that lead our immune cells to start attacking things they really don’t need to.

Leaky gut and mental health

Stress and mental health issues are associated with inflammatory bowel diseases and leaky gut and play a major role in thyroid related health issues.

Stress hormones and moods can result in reduced levels of mood-boosting neurotransmitters in the brain and increase the risk of developing gut disorders or flare ups of existing gut disorders. Several studies have found that patients with inflammatory gut conditions experienced worsening symptoms after stressful events. Chronic or long-term stress and depression is associated with more gut pain, leaky gut, and other inflammatory gut conditions like Crohn’s and ulcerative colitis. Stress can affect changes in the microbiota and the lining of the gut, and can further increase the gut inflammation. In animals, studies show that being under stress increases their intestinal permeability and inflammation and therefore also contributing to the worsening or causing a “flare-up” of Hashimoto’s.

We used to think that the brain sent direction down to control all parts of our bodies. We’re learning that a lot of the communication between the gut and the brain starts in the gut and goes up to the brain. Several studies show that in about half of people studied, gut symptoms arose before the mood issues did.

People who have gut disorders have a higher risk of developing anxiety or depression. Sometimes experiencing symptoms like abdominal pain, bloating, and discomfort can affect the quality of life and moods of people who have inflammatory bowel disease.

Some animal models of the inflammatory gut condition colitis promoted behavioural changes that are similar to mood disorders in people. Also, mice given an SCFA called butyrate seemed to experience an antidepressant effect.

These links between the gut and mental health are because of the “microbiota-gut-brain axis.” This axis includes many connections between the two of them, including through our nerves and hormones.

When the areas of the brain associated with stress are activated, this initiates the stress response. The stress response is twofold. First, it includes the release of stress hormones (hypothalamic-pituitary-adrenal axis – HPA axis) that go through the whole body. Second, it includes activation of the “fight or flight” (autonomic) part of the body’s nervous system. Both the hormones and autonomic nervous system affect the gut. And these can affect all three layers of the gut lining.

One of the key stress hormones of this HPA-axis is from the adrenal glands (the “A” in HPA). It’s the infamous stress hormone called cortisol. Cortisol is released into the bloodstream when we’re under stress. Cortisol directly affects the gut by reducing our ability to properly digest food, and instead prioritizes survival. It essentially prepares for “fight or flight” by slowing down the “rest and digest” functions.

FUN FACT: Mouse studies show that SCFAs may help to normalize the leakiness in not just our gut lining, but our “brain lining” (e.g. “blood-brain barrier”) too.

What you can do about leaky gut

When our “good” gut microbes are happy eating their favourite foods they have positive effects on our gut – crowding out the “bad” microbes and producing beneficial anti-inflammatory compounds like SCFAs.

FUN FACT: The type of microbes that live in your gut is established by the time you’re 3-5 years old. About 30-40% of it can be influenced by factors such as diet.

According to Aguayo-Patron, 2017:

“Diet is the main factor that influences gut microbiota composition.”

1 – Eat more fresh, unprocessed and minimally processed foods

We’re talking things like:

  • Fruits and vegetables
  • Nuts and seeds
  • Fish

This is sometimes referred to as an “old fashioned” diet. It includes fresh and minimally processed foods that are closer to the way they’re found in nature. These promote a healthy mix of the “good” gut microbes.

One of the reasons is because these foods contain higher amounts of fibre and “resistant” starch. Sugars and easily-digested starches are broken down and absorbed into the bloodstream as sugar. Resistant starches and fibre, on the other hand, are “resistant” to this process and make it all the way through our intestines to where most of our gut microbes live. These can then become food for our “good” gut microbes and promote their health.

Another way un-processed and minimally processed foods help our gut microbes is because of the lower amounts of trans and saturated fats, and higher amounts of healthy fats like unsaturated and omega-3 fats. Some studies show that diets high in undesirable fat tend to promote more “bad” microbes in our guts.

Another possible reason why fresh and unprocessed foods are beneficial is that some of the additives used in ultra-processed foods can also affect our gut microbiota. This leads us to the second thing you can do about leaky gut.

2 – Ditch the ultra-processed and fast foods!

These are the quick and easy foods that are:

  • Ready to eat
  • Ready to heat
  • Pre-packaged
  • Convenient
  • Fast

They tend to be high in calories, fat, sugar, salt, and contain additives. These are the foods that have a lot of sugar and easily digested starches that raise our blood sugar, and not a lot of fibre and resistant starches. They have more total fat, including trans and saturated fats. And, they tend to be not very filling and promote obesity.

These types of foods also promote inflammation and gut dysbiosis – factors associated with leaky guts!

People who tend to eat less of these, and more fresh and unprocessed foods tend to have happier gut microbiota, less inflammation, and a nice strong non-leaky gut lining.

3 – Pay attention to potential food intolerances

Some gut symptoms may be related to food intolerances. Certain people may have undiagnosed celiac disease, or be sensitive to gluten and can benefit from removing it from the diet. There are a lot of gluten-free foods available now, however, ultra-processed gluten-free foods are still ultra-processed and should be avoided in favour of fresh and unprocessed foods.

Also, some people are intolerant to certain carbohydrates called FODMAPS (fermentable oligo-, di-, and mono-saccharides and polyols). These are found in stone fruits, legumes, lactose-containing foods, and artificial sweeteners.

Ask your health professional to see if you should be tested for food intolerances.

4 – Reduce alcohol

Alcohol can stress our friendly gut microbes and can disrupt the function of our three-layered gut lining. It can cause bacterial overgrowth, and at the same time reduce some of the friendly “good” microbes like Lactobacillus.

FUN FACT: Some “bad” bacteria, including E. coli can produce alcohol, so this may be one of the ways that they contribute to leaky gut.

5 – Consider probiotics

Probiotics are live microorganisms that have a beneficial effect on human health. They are found in fermented foods like yogurt, kefir, kombucha, miso, kimchi, and fermented vegetables. They are also available as dietary supplements.

Infections and use of antibiotics, especially during the first months of life, can have a negative effect on our gut microbiota. If you have to take an antibiotic, ask your healthcare professional if you should also take certain probiotics to help reduce the impact on your gut microbiota.

Clinical trials are being done to test whether probiotics may benefit inflammatory gut conditions even without antibiotic use. More research is needed to confirm which amounts of which types of probiotics are the most beneficial for which conditions.

CAUTION: Before taking any supplements, make sure to read the label and heed the warnings. If you are taking other supplements or medications or if you have a medical condition, be sure to consult with a knowledgeable healthcare professional first.

Conclusion

Leaky gut, or “intestinal permeability” is linked with many conditions of the gut, the body, and the mind. While research is still figuring out exactly how this happens and what comes first, there are definitely steps you can take today to help optimize your health.

Eat more whole, unprocessed foods, and ditch ultra-processed foods. Reduce alcohol consumption and consider probiotics. And, if you think you may have a food intolerance, be sure to speak with your healthcare professional.

I hope this information was valuable to you. I’d be happy to hear from you–make sure to leave me a comment.

For more guidance and options on how to start a whole-foods based diet, check out my packages and meal planning options.

In good health,

Pamela

References

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