Back in the day, when I was training and competing in marathons and triathlons, I started to experience certain food sensitivities, poor sleep, diarrhea, and nausea. I put it down to stress, high training volumes, and working long hours as a personal trainer. Although doing a food sensitivity (IgG) test helped me remove particular foods that increased the symptoms (whey, eggs, gluten, cashews, alcohol, etc.), it wasn't enough to fix the underlying cause. I later found out I had a leaky gut, and once I fixed it, all of these symptoms went away.
Did you know that over two-thirds of your immune system resides in your gut? Antibiotics, aspirin, acid-blocking drugs, ibuprofen, chronic stress, overtraining, infections, food sensitivities and even toxins can affect your gut and, therefore, your immune system. The scary thing is, you don’t have to have gut symptoms to have underlying gut issues such as a leaky gut. Leaky gut can manifest as skin problems like eczema or psoriasis, heart failure, autoimmune conditions affecting the thyroid (Hashimoto’s) or joints (rheumatoid arthritis), mental illness, autism spectrum disorder, depression and more.
Leaky guy played havoc with my sleep, my ability to recover and, therefore, my health and happiness. Today, my gut health is significantly better, and I wish I had addressed the problem sooner.
What is leaky gut?
The official medical term for leaky gut is increased intestinal permeability, but most traditional medicine practitioners don’t know how to diagnose it or how to treat it. In traditional medicine, a leaky gut is not a thing. If you go to your doctor to talk about your arthritis, they’re not going to say, “How is your gut?” And yet, there is a tone of research connecting arthritis, and numerous other autoimmune diseases, with leaky gut. [1]
Before we get into what can cause a leaky gut, you need to know that your gut is a hollow tube that passes from your mouth to your anus. Anything that goes in your mouth and isn’t digested passes out the other end. One of the most important functions of the gut is to prevent foreign substances from entering the body. The gut wall is a thin cellular layer that plays the role of gatekeeper. It decides what is absorbed into the bloodstream and what doesn't. [2]
You can think of your gut lining like a coffee filter. You don't want the "ground coffee" leaking through, but you want the good stuff passing through. Leaky gut occurs when you get small holes in the filter and the unwanted "ground coffee" end up in your bloodstream. The "ground coffee" might be food particles that haven't been digested enough, or bacteria, a bug, fungus, or something that shouldn’t be getting inside your bloodstream. These unwanted villains can trigger inflammation and cause all sorts of symptoms.
Why is leaky gut bad?
Because toxic bacteria and food particles "leak" into your bloodstream, triggering inflammation can lead to allergies, autoimmune disease, depression, obesity, type 2 diabetes, heart disease, and even cancer, inflammation can also affect the brain and nervous system, causing anxiety, depression, irritability, and mood swings.
What are the symptoms of leaky gut?
You might experience loose stool, constipation, bloating, gas, stomach pain, headaches, nausea, fatigue, joint pain, swelling, asthma, congestion, skin irritations, skin problems (acne, rashes, or eczema) brain fog, fibromyalgia, sleep problems, and more.
Countless studies have shown that leaky gut can trigger autoimmunity. [3]
Why is leaky gut becoming more common?
The world we are living in is changing at a rapid pace. The food we eat, the chemicals we are exposed to, and the increased levels of stress impact our health. When it comes to recreation athletes and leaky gut, the following four factors are often the cause.
1. A toxic diet
One of the main reasons why digestive issues are becoming more common is our crappy food supply. Our food supply is full of pesticides, preservatives, emulsifiers, antibiotics, and chemicals designed to kill bacteria, including the healthy bacteria in your gut. We were not designed to eat these unnatural additives that have appeared in our food supply.
As an example, emulsifiers additives found in processed foods have been shown to break down this mucous membrane and cause bacteria and large food particles to leak through your gut into your bloodstream and cause IBS. [4]. In 2015, a review paper was published which suggested food additives irritate the gut and cause leaky gut, which then causes autoimmune disease. The review paper examined how specific food additives such as glucose, salt, emulsifiers, solvents, gluten, transglutaminase, and nanoparticles can cause leaky gut and lead to an overactive immune response (the beginning of autoimmune disease). The paper suggested that those with autoimmunity should avoid processed foods. [5]. If these foods are the cause of autoimmune diseases, shouldn't we be avoiding them full stop?
Further studies suggest a link between industrial seed oils and gut conditions. Industrial seed oils are high in omega-6 fatty acid and pro-inflammatory PUFA metabolites. [6] An imbalance between omega-6 and omega-3 fatty acids is correlated with irritable bowel symptoms (IBS). [7]
High omega-6 intakes from industrial seed oils have been shown to promotes chronic inflammation. The consumption of industrial seed oils is associated with elevations in inflammatory markers such as C-reactive protein, TNF-alpha, and interleukin-6. [8, 9]
Consuming high levels of omega-6 fatty acids alters the gut microbiota. It promotes gastrointestinal inflammation, thereby contributing to numerous gut issues commonly labelled as Irritable Bowel Disease (IBS) or Irritable Bowel Syndrome (IBS). Since industrial seed oils are the most abundant source of omega-6 fatty acids in the standard western diet, it stands to reason that we should all be avoiding these oils and replacing them with natural fats from olive oil, coconut oil, wild seafood, nuts and seeds, and healthy animal fats.
This can be very tricky if you eat out because many cafes and restaurants will use cheap industrial seed oils.
Gluten-containing grains are also a major contributor to gut issues. One of the main reasons I don’t eat wheat and other gluten-containing grains is that they contain a protein called gliadin, which has been shown to increase zonulin production, which has been shown to contribute to leaky gut directly. [10]
The main takeaway, remove processed foods, industrial seed oils and gluten-containing grains from your diet. Switching to a Paleo diet is one possible solution.
2. Taking NSAIDs
Millions of recreational athletes take over-the-counter painkillers like Advil or Aleve for random ache, pain, or cold symptom, without a second thought. Most often, NSAIDs do not treat the root cause of the pain. They treat the symptoms. Most don't know that those drugs, called non-steroidal anti-inflammatories (NSAIDs), are responsible for over 16,000 deaths per year [11].
NSAIDs can damage your gut lining [12] and cause leaky gut. Many scientific studies conducted over the past two decades show a correlation between NSAID use and leaky gut. [13] These medications include:
Advil / Motrin (ibuprofen)
Aspirin
Aleve (naproxen sodium)
Celebrex
Naprosyn (naproxen)
Lodine (etodolac)
Mobic
Nalfon (fenoprofen)
Daypro (oxaprozin)
Ansaid (flurbiprofen)
Cambia / Cataflam / Voltaren (diclofenac)
COX-2 Inhibitors
Suppose you are experience chronic pain, headaches, joint pain, muscle pain, nerve pain, and so on. You should seek a healthcare provider who can identify and treat the underlying cause of the problem, an integrative doctor, a naturopath or a functional medicine practitioner. It's doubtful that your local GP is going to help you here.
Natural anti-inflammatories such as Curcumin, Boswellia, and fish oil can offer some relief. By taking care of your gut, eating a healthy diet, getting quality sleep, and training sustainably can lower the chances of inflammatory issues. The need for pain medication will decrease.
3. Overtraining, under-recovery and poor stress management
I've put these together as one point as they are very closely related. Beyond poor diet, many other lifestyle factors impact gut health, such as overtraining (under-recovery), not sleeping enough, and not managing your stress levels.
Chronic stress causes cortisol dysregulation and subsequent weight gain, sleep disturbances, and even reduced life span. The gut is an integral part of the nervous system, so the brain can easily affect gut function. The biochemical changes that occur in times of stress have a significant and immediate impact on gut function. Stress affects the physiological function of the gut, but it has also been shown to cause changes in the composition of the microbiota. [14]
A 2017 study in mice found that exposure to stress compromised their gut microbiota in much the same way as a poor diet did. [15] When we think of the gut as the "second brain", it makes perfect sense that stress and the busyness of the modern lifestyle impact the gut.
Studies have shown that chronic stress can cause gastrointestinal diseases such as gastroesophageal reflux disease (GERD), peptic ulcer disease, IBD, IBS, and even food allergies. [16] Stress-induced alterations to microbial flora increase the likelihood of leaky gut.
Chronic stress can increase food sensitivities. Food sensitivities cause inflammation which is also a stress on the body. It's a vicious circle that can quickly spiral out of control. This is why it is important to remove any foods that are causing symptoms until you heal the gut. A food sensitivity is not like a food allergy. Once you fix the gut, you should be able to eat these foods again.
Exercise has been shown to boost beneficial gut bacteria, including anti-inflammatory short-chain fatty acid (SCFA)-producing bacteria, thus inhibiting gut inflammation. (17, 18) Unsurprisingly, a sedentary lifestyle is associated with an increase of inflammatory molecules into the gut. (19). But here's the kicker, while moderate exercise is good, more is not necessarily better. Excessive exercise increases intestinal permeability and can negatively alter the gut microbiota. If you're under a lot of stress or have chronic inflammation, you should focus on gentler activities and limit strenuous exercise. (19, 20, 21)
While high-intensity exercise routines provide some health benefits, there is a fine line between training hard and overtraining. The same can also be said for the high volume of steady-state cardio. Engaging in high volumes of physically demanding activities too frequently or too intensely can contribute to many different symptoms of overtraining. Chronically high cortisol levels can increase your risk for a variety of health issues, such as sleep disturbances, digestive issues, depression, weight gain, and memory impairment. [22] Excess cortisol also encourages fat gain, particularly around the abdomen. [23]
Overtraining goes beyond too many hours spent at the gym. Extreme volumes of high-intensity exercise can increase cortisol levels and lead to burn-out. Certain exercise routines can push the body’s stress response too far, causing serious damage to one’s health in both the short and long term. Overtraining has been shown to affect blood levels of important neurotransmitters such as glutamine, dopamine and 5-HTP, leading to feelings of depression and chronic fatigue.
Exercise is physical stress placed on the body, and the stress of overtraining can cause a leaky gut. This again hints at the importance of balance. Not all exercise is healthy. In fact, it can be harmful to your health when stress levels are left unchecked.
4. Excessive Alcohol Consumption
Yes, excessive alcohol contributes to a leaky gut [24, 25] and an unhealthy gut is not the place for alcohol. Research shows that people who regularly drink alcohol, including excess, have guts that look very different from those who drink little to no alcohol. [26] Alcohol can also lead to a leaky gut and interfere with how the immune system functions, leading to increased inflammation within the gut and elsewhere in the body. [27, 28]
To fully heal a leaky gut you have to go through a sustained period of time where you literally abstain from ALL contributing factors.
Alcohol damages the pancreas, which is responsible for the secretion of digestive enzymes. [29] Digestive enzymes help us break down the food/nutrients to absorb them into our body for growth, repair and health [30]. Partially digested food can cause excessive fermentation in your gut (hello bloating, gas and loose stools). If you continue drinking alcohol whilst suffering from leaky gut, you will end up with a vicious cycle of indigestion and poor nutrient absorption. The definition of a healthy gut is the optimal digestion, absorption, and assimilation of our food.
Excessive alcohol consumption may result in bacterial overgrowth and dysbiosis and the overall composition of the gut microbiome [25,28]
Cutting back on alcohol consumption can:
Improve hormone regulation
Increase fertility
Reduce inflammation
Strengthen the immune system
Improve gut health
Decrease cravings
Improve live function and detoxification
Improve pancreas function and nutrient absorption
Decrease body fat
.... and more
Here’s the takeaway. Leaky gut and bad gut flora are common because of the modern lifestyle. If you have a leaky gut, you probably have bad gut flora and vice versa. And when your gut flora and gut barrier are impaired, you will be inflamed. To adequately address these conditions, you must rebuild healthy gut flora and restore the integrity of your intestinal barrier. This is especially true if you have any autoimmune disease, whether you experience digestive issues or not.