Did you know?
Allergies, autoimmunity, and mental health have been linked with gut problems
That’s why, I focus on healing leaky gut, no matter what your MAIN issue is when you come to see me. Whether it be fatigue, weight, moods, digestive issues, poor immunity or autoimmunity, alcohol or sugar addiction, poor cognitive function, allergies… or something else, we will very likely end up working on your gut health.
The all-important gut
The reason for this is that the gut is a complex, alive system, and a foundation of health. Yes, the digestive tract is not just a tube that absorbs nutrients and gets rid of waste. It’s key to the overall health of our bodies and minds.
We know how important it is to get all of our essential nutrients from food – and this is a big part of what our digestive tract does. But, there is way more to the story than just that. When the gut is not working properly, symptoms can appear. Yes, typical gut and abdominal symptoms, like IBS, but also other seemingly unrelated symptoms.
Let’s look at one gut problem in particular – leaky gut, a.k.a. ‘Intestinal permeability’.
You may have heard about this lately. It involves tiny “leaks” or perforations in our gut lining. The openings – referred to as ‘junctions’ – become wide open – more open than is functionally useful, and allow more than just the needed nutrients and water into our bodies.
Researchers are looking at this, and I want to share the latest news with you, as well as give you some helpful strategies to optimize your gut health, for overall health!
What is “leaky gut” linked with?The “gut” refers to the the intestines, which are part of the digestive system, which are located in the abdomen or ‘abdominal cavity’. It’s an alive place in a very complex “tube” that acts as a gateway or sentry.
It digests and absorbs nutrients and water. It ‘decides’ what will enter the internal circulation of the body, and what must not get by. It prevents toxins and “bad” microbes from being absorbed, and it shuttles all the waste along to be eliminated.
You may think that symptoms of a leaky gut are felt in the gut, and you’re right…to a point. But sometimes the first sign of a leaky gut is acne, or something else that seems very unrelated!.
Would you be surprised to know that lots of other symptoms and conditions are linked with leaky gut?
Leaky gut has been associated with:
- Autoimmune diseases (e.g. Type I diabetes, celiac disease, Hashimoto’s thyroiditis etc.)
- Inflammatory Bowel Diseases (e.g. ulcerative colitis, Crohn’s)
- Psychological stress and mental health issues
Researchers are still figuring out the exact role that leaky gut plays in these conditions. Either way, the connections are there, and there are things that you can definitely do to improve your gut health. I will tell you about many of them…
But first, how is our gut structured, and what can promote it to leak?
Gut structure – Three layers of our gut lining
Our guts have a three-layer lining that helps to allow things we need in, and keep harmful things out.
The first (outermost) layer.
This layer is just one-cell thick! Laid out flat, this layer makes up the largest surface area between the internal circulation of our bodies and the outside world (i.e. what we eat and drink). It’s a barrier that physically prevents toxins, undigested compounds, and bacteria from getting into our bodies. Yet, it absorbs the nutrients and water we need.
This layer has at least seven different types of cells, and 90% of them are one type called “enterocytes.” These enterocytes actively absorb what we need and keep out what we don’t. They also help to create and regulate the other two layers.
FUN FACT: Most enterocytes are replaced with new ones every 3-5 days or so.
Enterocytes are held together with different types of bonds. The one most studied is called a “tight junction.” These tight junctions are made up of several types of protein. When they loosen, it creates tiny holes (or permeations) in this first layer since the cells are not “stuck” together as much as they should be.
The mucus layer
The second layer is mucus. Before you get all grossed out, I want to point out that this is a beautiful, useful mucus that keeps everything healthy. We want that mucus layer to be nice and thick to provide a better barrier between the one-cell layer of enterocytes and protect them from “bad” bacteria that can get in there.
This mucus provides physical separation between the outermost enterocyte layer and the microbes and food that are inside the centre, or “lumen,” of the gut. It also contains special proteins that help fight against invaders. This mucus and its special compounds are produced by the enterocytes.
FUN FACT: Animal studies show that mice fed a diet low in fibre had thinner mucus barriers.
The third (innermost) layer inside our gut lining is our friendly resident gut microbes. I’ve written at length about how our guts contain billions of microbes – over 1 kg worth. Taken together, they’re sometimes referred to as a “superorganism” or “the metabolome”.
These microbes include bacteria as well as other types of friendly microbes. This layer of gut microbiota has two major functions to help promote a healthy gut lining:
They crowd out “bad” bacteria by taking up space and eating the “good” food (i.e. fibre and resistant starch, which we’ll get into in a bit). They help to regulate the digestion and absorption of nutrients to nourish the first-layer enterocytes. One of the types of compounds they produce are great things called “short chain fatty acids” (SCFAs). These are considered to be anti-inflammatory and are also used as fuel for the enterocytes.
When the three layers aren’t working optimally, the tight junctions loosen, and leaks occur. This allows unwanted things to enter into the body’s circulation. This is how gut health affects our overall health.
Leaky gut and our gut microbes
Our friendly gut microbes, the third innermost layer of our gut, include hundreds of types of microbes. Some of the main types of bacteria are Bacteroidetes and Firmicutes (e.g. Lactobacillus). We think problems with our gut microbes might actually begin the whole process of leaking guts.
According to Sturgeon and Fasano, 2016:
“It is now clear there is a symbiotic relationship between the microbiome and the host. As early as 2001, it was described that commensal bacteria have an effect on intestinal permeability.”
Here’s how we think this happens, based on the current research:
The third innermost layer of the gut lining, the microbiota, get out of balance.
Inflammatory molecules (including zonulin) are released, and fewer anti-inflammatory ones (like SCFAs) are available.
This inflammation disturbs the tight junctions in first layer of enterocytes, hence creating tiny leaks, which allow passage of harmful compounds into our bodies.
It starts when the gut microbiota are in dysbiosis (an “imbalance” of “good” and “bad” microbes). This promotes an inflammatory response because some of the “bad” microbes are pushing out the “good” ones that produce the anti-inflammatory short chain fatty acids (SCFAs).
Leaky gut and short chain fatty acids
SCFAs are anti-inflammatory and are also used as fuel by the enterocytes.
Some of these SCFAs promote the production of the mucus layer (the second layer), and even help to improve the tight junctions in the enterocytes in the first layer. They produce the SCFAs when they eat fibre and resistant starch.
FUN FACT that is NOT FUN at all: One study looked at children who were at risk of developing type 1 diabetes (which is an autoimmune condition). Researchers found that some who had an increase in one of the “bad” microbes went on to develop autoimmunity months later which led to type 1 diabetes. (Keep that in mind the next time you see a diabetic 6 year old. The child’s mom might not be feeding them sugar, they may just have bad gut bacteria).
Leaky gut and zonulin
Another possibility that researchers are looking at is that some of these “bad” bacteria produce a toxin that mimics the protein called zonulin.
Zonulin is associated with intestinal permeability, and leaky gut. There’s a caveat here: serum zonulin is not 100% always a reliable marker for intestinal permeability…but it is pretty darn good.
Zonulin is a protein that is naturally released by our enterocytes when they’re exposed to certain things we eat. Namely, wheat, “bad” bacteria on our food, and gliadin, (part of the gluten protein found in gluten-containing grains).
All of this increased inflammation then irritates the gut, which can result in loosening of those tight junctions.
Based on the research so far, this is the way we think we develop leaky guts.
But, how does this relate to autoimmunity?
Leaky gut and allergies
Well, to start, blood levels of zonulin tend to be higher in people with autoimmune conditions like celiac disease and type 1 diabetes. And 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, or hypersensitive.
The logic of allergies is faulty. It’s like the body cannot think logically.
When our immune system is activated to fight things that are not harmful, like certain foods, pollen, or pet dander, the body is like the POTUS going after Mexican children, as if that will improve the employment rate for white males in the rust belt areas of the US.
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, and all it causes is pain, with no gain.
Leaky gut and autoimmunity
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.” It’s like when everyone stops listening to each other, and civil discussion breaks down. Instead of working together to solve a real threat like global warming, we fight each other over issues of gender or dietary preferences.
For example, type 1 diabetes (an autoimmune disease) occurs when our immune system fights the insulin-producing cells in our pancreas. After continued inflammation, enough of these cells die and we eventually need to start monitoring our own blood sugar levels and provide our bodies with external insulin. This occurs more often in people who have type 1 diabetes in their families.
Many things can contribute to autoimmunity, and leaky gut is a bigger factor than we once thought. This is because of the impact of allowing undigested food, toxins and bacteria to enter our bodies. Our immune system tries to fight them.
When the gut leaks
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 time, the immune response happens on the other side of the first layer of enterocytes, inside our bodies and bloodstreams.
This immune response to things that “leaked” into our bodies can cause the release of even more inflammatory compounds. 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 infancy. The first 5 years are a critical time. 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, Leaky brain – Leaky gut and stress
Stress and mental health issues are associated with inflammatory bowel diseases and leaky gut.
Stress hormones can result in reduced levels of mood-boosting neurotransmitters in the brain.
They also increase the risk of developing gut disorders, or having flare ups of existing gut disorders. Several studies have found that patients with inflammatory gut conditions experienced worsening symptoms after stressful events.
In animals, studies show that being under stress increases their intestinal permeability and inflammation. Chronic or long-term stress and depression are 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.
We used to think that the brain sent info in a downward direction to control all parts of our bodies.
Turns out, not so much.
As discussed in my other posts, we’ve learned 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.
In some animal models, colitis (an inflammatory gut condition) promoted behavioural changes similar to mood disorders in people. Also, mice given an SCFA called butyrate (as in, the SCFA in butter) seemed to experience an antidepressant effect.
Furthermore, a recent study was published that suggested a link between zonulin and ADHD. The study results add to the evidence linking leaky gut and other gut issues to behavioural disorders like ADHD, autism, sensory processing disorder, OCD, and many others.
This study found that kids with ADHD had more zonulin in their blood than average. The kids with the highest zonulin levels were the most socially impaired.
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. Hence, Leaky gut, Leaky brain.
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
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 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 opposite of the last types of foods. These are quick foods that are:
- Ready to eat
- Ready to heat
- Fast and Easy
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 – Try making and drinking bone stock
Bone stock, often referred to as bone broth, is obviously not high on a vegan’s go-to list of drinks.
But, if you can stand it, try it. It’s incredibly healing to the gut lining. All the amino acids contribute to a healthy gut. So much so, sometimes I feel like I am a broken record regarding consuming this stuff! It is something I highly recommend you make a habit of making.
If you are buying the types of foods that are not as fast and ready to eat, and more focused on quality, you’ll probably be getting more bone-in cuts of meat. For example, one way to afford the switch from regular to organic chicken (a must-do move) is to switch from boneless, skinless breasts, to whole organic chickens, or bulk wings.
The tricks is, to keep all the bones after eating the bird. Read my post for all the details. If you really don’t like this idea, try including more gelatine, or jello made with fruit juice instead of sugar. If you are into supplements, collagen peptides or glutamine would fall into a similar category, as would DGL.
4 – Pay attention to potential food intolerances
Keep a journal! Some gut symptoms may be related to food intolerances, but they may be intermittent or delayed. 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 for 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.
5 – Drink less booze
Argh, no one likes this one. Yet 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.
6 – Consider probiotics
Probiotics could mean popping a capsule/a dietary supplement, or eating food. We mean live microorganisms that have a beneficial effect on human health, of the type found in fermented foods like yogurt, kefir, kombucha, miso, kimchi, and fermented vegetables.
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. In fact, it is a good idea to call the manufacturer, whether you have a health issue or not, as they can help you pick the right product for your needs.
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.
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 bone broth and probiotics. Let me know if I can help with any of this! And, if you think you may have a food intolerance, be sure to speak with me or another healthcare professional you trust.
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