What is Leaky Gut and What Does it Have to Do with Your GI Symptoms, Athletic Performance and Long-Term Food Intolerances?

Just after an incredibly warm, humid and ROUGH marathon in which my gastrointestinal system barely held on to the end, and then subsequently fell completely apart at the finish line. In a prelude to what’s below, I was also stressed out for weeks before that race.

Leaky Gut, also called increased intestinal permeability or gut permeability is when the tight junctions, which are the space between each of the cells that line the small intestine where nutrient absorption occurs, loosen a little and allow larger food particles and bacterial fragments into the bloodstream, potentially setting off an immune response and inflammatory reactions (1).  

If you have a digestive disorder or gut health problems, it’s generally safe to assume you have a leaky gut. Likewise, leaky gut symptoms can present in a wide variety of ways across multiple body systems – not just in the digestive system.  

Leaky Gut is associated with Irritable Bowel Disease (IBD), Crohn’s Disease (CD), multiple sclerosis (MS), rheutamoid arthritis (RA), type 1 diabetes (T1D), asthma, necrotizing enterocolitis, and autism spectrum disorder (2), as well as celiac disease, non-celiac gluten sensitivity, various skin disorders (if your skin has problems–then you have digestive problems), and more (3). However, we haven’t yet determined whether leaky gut is a cause or consequence of these disorders.

The Athlete Component

What is not as well known to a lot of the run long and run harder crowd is that sustained endurance activities, particularly the jostling and pounding that we do as runners, can and will cause a fair bit of leaky gut symptoms. If you consider the anatomy and physiology of this region of the digestive system, it’s easier to see why. Picture a person running a three (or four, or nine) hour marathon or ultra endurance race, or a series of training runs day after day and throughout weeks and months. The race and many of the runs leading up to the race is going to be a hard and a long effort (sometimes both), which we also will sometimes begin without feeling as recovered from the last effort as we’d prefer. Then, while running, we down any number of foods and food-like substances to provide fuel to sustain the effort and to “train the gut.” This fueling on the go is something the digestive and nervous systems are arguably not designed for. We’re “supposed to” be in rest and digest mode while we’re processing those calories. So utilizing them on the go is a stress to the system.

Then there’s the gut itself. At the small intestine, the cells between it and the bloodstream are approximately one cell thick. This is because this is the site where broken down nutrients move through to be transported to the liver and other regions of the body for use. It’s super thin so nutrients can get where they’re supposed to go. But one cell, and the space between it and the next one, is pretty easy to damage with jostling and stress. So even with a perfect diet, a hard long run (or even a hard shorter run) can cause some damage down there. This is why many people have digestive complaints for three to five days after a race or hard effort. That’s exactly how long it takes for the epithelial lining to turnover into completely new cells!

But what makes leaky gut become chronic, thus inviting long-term digestive (or widespread) symptoms?

There are several lifestyle factors that can also lead to and sustain a leaky gut including stress (a BIG one!), lack of sleep, eating inflammatory foods, alcohol, antibiotics, oral contraceptives, prescription medications, exposure to environmental toxins, and frequent use of NSAIDS such as ibuprofen. Likewise, nutrient deficiencies, poor digestion due to digestive enzyme deficiency, overeating in general, wrong ratio of dietary fats, gut microbe dysbiosis and (sometimes hidden) other food allergies can also contribute. Oofda! That’s a lot of factors that can be working against us.

That Villain Gluten and the Bacterial Connection

Dr. Alessio Fasano, a leading scientist who studies celiac disease and related pathologies, discovered an enterotoxin called zonulin a few years ago. Zonulin disassembles the tight junctions in the intestinal lining, allowing pathogens through and thus causing more intestinal permeability. Dr. Fasano’s research team found that zonulin release is primarily triggered by both bacteria and gliadin. Gliadin is part of the gluten protein complex (2.) Hence the reason many of us are either mildly or definitively reactive to gluten-containing foods, at least some of the time.

Before developing increased intestinal permeability, changes in the gut microbiota have also been shown to occur, which, given that zonulin release is often triggered by bacteria, suggests that the bacterial change occurs first, and then zonulin release assists the epithelial tight junctions to disassemble, leading the way for subsequent disorders or diseases to develop after sustained leaky gut-inflammatory reactions. It has been suggested that an environmental stimulus, (that list above including stress, gluten, a virus, inflammatory diet, etc.) first causes the change in the gut microbiota (2).

How to Heal

Healing chronic leaky gut often takes a many-pronged approach. We have to remove as many of the things that are causing it as it’s appropriate to. For those of us who aren’t willing to give up endurance athlete lifestyles, that means eating a diet appropriate for the individual, repletion of nutrient deficiencies, and lifestyle tactics (that stress relief component!) become particularly important.

Want to Know More?

A leaky gut is one of the primary categories of digestive imbalances I look for when working with individuals clinically with digestion-related and sometimes widespread symptoms. Often when we’re experiencing chronic GI distress, fatigue, and malabsorption of foods and nutrients, there will be imbalances in several categories, and we begin working on the areas that appear most pertinent. I shared more about this topic in the nervous system’s role in part 1, the immune response and subsequent inflammation in part two, gut microbes and dysbiosis in part three and the importance of chewing our food in part four.

And If you’re tired of dealing with your wonky GI symptoms and fatigue, and would like to get back to feeling and training well, I invite you to reach out to me for more personalized support.

References:
1). Lipski, E. (2012). Digestive Wellness (4th ed). McGraw Hill: New York, NY.
2). Sturgeon, C. and Fasano, A. (2016). Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue Barriers, 4(4). https://doi.org/10.1080/21688370.2016.1251384.
3) Kneessi, R. (2017). NUTR 635: Adverse Reactions to Food. [Lecture]. Maryland University of Integrative Health. Retrieved from: https://learn.muih.edu

An especially important, and often overlooked, key to better digestion

One of my mentors recently shared a phrase that’s stuck with me, and really helped in my day to day. She shared in an almost offhand way, Rushing is ego. It feeds self-importance. As someone that tends to perpetually feel rushed and scattered and multi-tasks far more than I should, her statement was like a gentle but stern hand on my shoulder. And a reminder that rushing never makes me feel better in any way.

One of the main areas I tend to rush, multi-task and be scattered is when eating. Alone and left to my own devices, I tend to rarely eat without distraction. And when William and I enjoy meals in the evenings together, catching up on our days and eating while talking (quickly) is more the norm. A couple years ago, recognizing a pattern in myself, I started an experiment of several days of eating with no distraction. What I realized from that experiment was that I’ve tended to avoid being alone with my thoughts at meals because it brought awareness to things I didn’t want to feel. A few months later, I reinstated the distraction free eating practice, having lunch every day outside on the patio without technology or (my weakness), things to read. Instead I simply enjoyed my meals, listened to the summer bugs and watched the hummingbird’s daily visit to the pink zinnia. It was lovely and stress-reducing. And a few weeks into that new habit, I noticed my digestion had really improved, and that I’d begun to feel a lot better in my autoimmune pain and other symptoms. And quite noticeably, I was running and recovering really well during that time.

Summer ended and the practice gradually fell away. I went back to distracted eating and well, I’d notice my digestion was off, stress ran higher, and I didn’t tend to enjoy my meals much because I wasn’t paying attention to actually eating them!

Today, I’ve got a short but incredibly substantial tip if you’re struggling with poor digestion, GI pain (whether it’s general or after a tough workout), bloating, excess gas, etc. And it also helps A LOT if you tend to be generally mentally scattered or anxious. It’s one that you don’t have to spend a ton of money on – actually it’s free! It doesn’t take special skills or preparation. And the process of eating your meals and the hours afterward (those poor digestion side effects), will be much more enjoyable.

Are you ready?

For the next few days, try really chewing your food.

And by that I mean, chewing every bite until it’s broken down into a mush. This means you might chew 20-35 times per bite. Yes, really.

That’s going to be tolerated better than it used to…

Before food ever gets to our stomach or small intestine where stomach acids and digestive enzymes contribute to the chemical process of digestion and then nutrient absorption, digestion actually begins in the brain (just thinking about and then smelling food) and in the mouth. Digestive juices, saliva, enzymes, and digestive hormones are released and begin flowing in anticipation of a meal. Then saliva contains enzymes that further initiate digestion. Likewise, mechanical breakdown of food with our teeth is incredibly important so the enzymes, gastric acids, and hormones can then take over further along in the process.

Some people like to count the number of chews per bite, so go ahead if this helps you to establish the practice. Focus on chewing every mouthful until it is liquid.

The father of modern medicine, Hippocrates, is often quoted as saying that all disease begins in the gut. Interestingly and unsurprisingly, most traditional (and much older) medical systems around the world believe the same. For all I know, some wise sage (or perhaps just my wise mentor) also came up with that phrase about rushing and feeding ego’s self-importance. Especially now in mid-December leading up to the holidays — especially now when Covid-rates are increasing stress (again), help your digestion out a little, and actually enjoy your food, by chewing it a little more.

Impaired digestion and subsequent absorption of food is one of the primary categories of digestive imbalances I look for when working with individuals clinically with impaired digestion. Often when we’re experiencing chronic GI distress, fatigue, or anxiety, there will be imbalances in several categories, and we begin working on the areas that appear most pertinent. I shared about the nervous system’s role in part 1 of this topic, the immune response and subsequent inflammation in part two, gut microbes and dysbiosis in part three and I’ll explain remaining categories in future articles.

And If you’re tired of dealing with your wonky GI and would like to get back to feeling and training well, I invite you to reach out to me for more personalized support.

connecting the gut and the nervous system

I had an emotional couple of days last week. If you know anything about the Enneagram personality archetyping, I’m most definitely a type 4, so deep and vast emotions are a familiarity for me. That aside, I was emotional. I cried a fair bit and felt my own little volcano of melancholy come out in periodic waves. One such wave was on a run last Thursday morning. Most long-term runners know certain runs can be incredibly therapeutic and where we work through challenging emotions. This was one of those.

When I returned to the house after finishing and began my cool down stretch, I had a familiar mild, dull pain in my abdomen set in, and it continued throughout the day. As an old familiar, I knew exactly the cause of the pain when I first noticed it. As a sensitive child, I grew up with routine anxious ‘tummy aches,’ on Sundays before a new school week began, couldn’t eat before stressful events, and generally would feel knots in my middle when emotionally distraught.

Unsurprisingly, there’s a reason for this.

For anyone that likes to show up to an athletic race early in the morning, stand in line at the porta potty, and then hope to put your best foot forward in your event of choice, or perhaps engage in a similar nervous-inducing event in another area of life like a job interview, you know that when you’re anxious, nervous, or otherwise stressed, digestion is quite a bit off. That’s because the gut and the brain are intimately connected. The nervous system has several branches and one section, the enteric nervous system (ENS), is often called ‘the second brain.’ The ENS is the section that runs through our digestive system and is connected to the actual brain through a large nerve that runs through are central body and communicates in both directions. This is called the vagus nerve.  When we have a really emotional episode, like I did, our brain can send chemical messages to the gut that change our gut bacteria, leading to low-grade gut inflammation and possibly GI distress. Similarly, if we have a particular imbalance in the gut itself—through food that doesn’t sit well or isn’t best for us, or inflammation and excessive permeability to the gut lining for another reason, we often notice behavioral changes as well. For example, persons that have chronic GI distress often also experience one or several mental health symptoms, including anxiety, depression, fatigue, confusion, brain fog, poor memory, migraines, and more.


When we have continued stress, whether in our body or in our mind, the nervous system slows down or impairs digestive function. This is why it’s best to not eat when we’re in a stressful mindset or running out the door in the morning before work or while rushing between meetings. And why one simple way to improve digestion is to single-task while we eat. That is, eat in a quiet, peaceful environment and do only that. Just eat, enjoy, and actually chew the meal. And its why major stressful life events often precede major health symptoms and then diagnoses. If you struggle with digestive conditions such as one of the Irritable Bowel Diseases (Crohn’s, Ulcerative Colitis, Diverticulitis, etc.), IBS, GERD, ulcers, chronic constipation or diarrhea, and any autoimmune disease, your condition will often respond favorably to stress-reduction techniques. For athletes with any of these conditions, we often argue that our physical activity is our source of stress reduction. That may be true—in theory—but often our activity load is contributing stress when our physical and mental systems are way out of balance.

True rest and relaxation, such as spending an hour or more per day doing absolutely nothing, deep breathing, meditation or prayer practices, spending quiet time in nature, gardening, yoga, painting, or other quiet activities without a screen are sometimes exactly what we need most to begin digestive healing – not a fancy, stressful, rigid new eating plan. (Gasp! I know; how dare I say that as someone that works with people on food!)

Otherwise, I love to work with herbs for the nervous system. In fact, nervines, the category of herbs that work on the nervous system, are by far the ones I work with and recommend the most. Lavender in this blueberry lavender smoothie bowl, and skullcap, tulsi / Holy Basil, lemon balm, and lavender in this stress-reduction tea or herbal latte are just a couple relax-inducing herbal ideas to consider.

The nervous system is one of the primary categories of digestive imbalances I look for when working with individuals clinically with impaired digestion. Often when we’re experiencing chronic GI distress, fatigue, or anxiety, there will be imbalances in several categories, and we begin working on the areas that appear most pertinent. I shared about the immune response and subsequent inflammation in part two, gut microbes and dysbiosis in part three, and a tip to support digestion and absorption in part four. I’ll explain remaining categories in future articles.

And If you’re tired of dealing with your wonky GI and would like to get back to feeling and training well, I invite you to reach out to me for more personalized support.

References:
1: Lipski, L. (2012). Digestive Wellness (4th ed.). New York, NY: McGraw Hill.