January 9, 2014

Digestion for (not-so) Dummies: Small Intestine Pt.3 - Gluten & Leaky Gut

Show of hands: who’s been anxiously awaiting the next post in this series on digestion? (*Crickets.*) Whether you’ve been on the edge of your seat hoping I’d get around to it soon or not, here it is.

Last time, we talked about the concept of increased intestinal permeability, aka “leaky gut,” and all the gnarly health problems that can result when bricks start crumbling in the fortress walls of the small intestine. We mostly talked about autoimmune conditions, but that’s barely scratching the surface. A leaky gut can cause all kinds of havoc on our bodies and our minds.

I left off last time saying that we should dedicate an entire post to gluten, because it’s one of the things responsible for causing leaky gut. So here we go.

Warning: this post is quite long. There’s a lot to cover, and I think most of it is pretty important. If we’re going to make sense of this, there’s no point in short changing ourselves. So go get yourself a tub of popcorn carrots & celery, get comfy in your chair, and pretend this is a movie. (One with subtitles, since there's a lot of reading to do here, hehheh.)

Gluten is a protein found in wheat and botanically related grains, like barley and rye. It’s also found in spelt, kamut, and einkorn—ancient varieties of wheat that you sometimes see in fancy-schmancy breads and crackers for which they’ll charge you double for these seemingly mystical and exotic grains. (Thanks to modern food processing, however, gluten is in darn near everything, including things that have nothing to do with wheat and aren't even foods—like lipstick.) Okay, so it's a protein. No big deal, right? Au contraire, mon ami. According to Drs. Thomas O’Bryan and Alessio Fasano, arguably two of the most well-respected experts on gluten sensitivity, no humans have the ability to digest gluten. None of us. (We lack the enzymes required.) This was news to me, as I’ve long understood that there are some people who can’t digest it, but I thought I was one of the lucky ones. I was wrong. Turns out it’s all of us. The difference is only in the degree to which this affects us.

What do I mean by “the degree to which this affects us?” Well, there are basically three camps: the first is celiac disease, the second is non-celiac gluten sensitivity, and the third is your average Joe/Jane out there who has no identifiable issues he/she can tie to a gluten intolerance (but who, by virtue of belonging to the illustrious Homo sapiens tribe, cannot digest gluten).

We like holes in our Swiss cheese, 
but not in our gut!
Celiac disease is usually referred to as “the tip of the iceberg.” The whole of gluten sensitivity is huge—like an enormous iceberg—but until recently, the only part of it we could “see” – i.e., the only part of it formally acknowledged by the modern medical establishment, was celiac disease. Remember when we talked about the small intestine being like a shag carpet? We also used the analogy that it’s like a screen door, with teeny, tiny holes that allow only very specific types and sizes of molecules to pass through. Well, if you have celiac disease, when gluten hits your small intestine, it is the thing that comes along and punches big holes in that screen, thus allowing bigger “stuff” to pass through into the bloodstream. That’s the main idea here: gluten causes a leaky gut. (To be specific, the gliadin portion of the gluten protein interacts with a protein called zonulin, and the zonulin causes the tight junctions between intestinal cells to loosen up.)

People with overt celiac disease are usually diagnosed via an intestinal biopsy. Doctors are able to look at the cells lining the small intestine and see how much damage has been done. Lots of damage? Likely celiac. (Remember that shag carpet analogy? Celiac disease is sometimes diagnosed by identification of “total villous atrophy.” That means total destruction of the villi—those individual shags that are so important for the absorption of nutrients. Celiac disease is like your shag carpet turning into a tile floor. The shags (villi) are toast, and you are not going to absorb the good stuff in your food. All organic, grass-fed, hormone-free, local, biodynamic and blessed by the gods? Doesn’t matter. If your intestinal lining is shot, you ain’t absorbing nutrients, no way, no how. It doesn’t matter how high the quality of your food is. This is why some of the more classic signs of celiac disease are weight loss (and not in a good way…more like what’s known as “wasting,” because you lose muscle mass and lean tissue besides losing body fat), bloating, diarrhea, intestinal cramping, lethargy, and overall feeling like dog doodoo. Plus, let's remember all the other fun things that can logically result from a malfunctioning small intestine. Possible long-term complications from not absorbing vitamins and minerals include osteopenia, anemia, depression, fatigue, infertility, dry skin, brittle nails, and more.

Now let’s talk about category number two—non-celiac gluten sensitivity (NCGS). Here’s where things really get interesting. See, it’s easy to see why people with celiac disease need to avoid gluten. Their symptoms are severe and, in some cases, completely debilitating. Sometimes they’re also immediate, as in, these people are running to the bathroom within just a little while of accidentally consuming gluten, so it’s easy for them to connect their intestinal symptoms with the ingestion of gluten. But what about the others? The people who are sensitive to gluten but don’t have celiac? How can you tell if you’re sensitive to gluten if you don’t have any intestinal symptoms? This is the million-dollar question, and there are about a million different things that could tip you off. People with NCGS have health issues that have nothing to do with the intestines and sometimes they have none of the small intestinal villous atrophy seen in classic celiac. That’s why it took so long for medical professionals to associate these other issues with the consumption of gluten—because they were looking specifically for the destruction of the villi, which is often absent in those with NCGS. Instead, these people experience what is known as “extraintestinal effects.” That is, effects from the ingestion of gluten that are felt elsewhere in the body, outside the intestine.

We just said that gluten is one of the main things that causes a leaky gut. And as we covered last time, if your gut is leaky, larger molecules of undigested food are going to pass through that compromised barrier, as are pathogens, microbes, and other undesirables that would have been neutralized if your digestive function was up to par.

A key thing to know is that upwards of 60-70% of the body’s immune system is located in the GI tract. It’s called GALT: gut-associated lymphoid tissue. If the integrity of your gut has been compromised, then this key first-line of defense against invaders (the aforementioned food-borne pathogens, microbes, etc.) can’t do its job effectively. What does that mean? Simple: you get sick more often. If 70% of your immune system has been cut off at the knees, how do you expect to fight off colds, the flu, and whatever else is going around? Of course, stomach acid should neutralize these things long before they even reach the small intestine, but we all know modern living is a recipe for low stomach acid. For an example of how this might play out in the real world, let’s say we’ve got a hundred people at a picnic. Fifty of them have low stomach acid and some degree of leaky gut, and the other fifty have powerhouse GI tracts. They all eat the same potato salad that was sitting out in the heat all day, but only half of them get sick. If you had to guess, which half would you suspect? (Correct answer: the ones with compromised GI tracts. Not only did their low stomach acid fail to neutralize the pathogens initially, but their leaky gut allowed them to pass through into the bloodstream and make them sick.)

Are you the type who’s always coming down with something? 
Maybe it’s your gut.

Do you know anyone—maybe it’s even you—who seems to be allergic to a million different things? Strawberries, chicken, almonds, corn, spinach, and on and on? (You wonder how these people are able to survive outside a bubble or an iron lung or something.) What’s likely going on is not that they're genuinely allergic to sixty-five things. What they've got is a leaky gut and all those foods are passing through it, undigested, and the immune system is mounting its defenses, which they experience as an allergic reaction. (Credit where credit is due: Diane Sanfilippo said something like this on the Balanced Bites podcast and she could not be more right.)

But that’s nothing. Remember when we talked about autoimmune conditions? This is when the immune system gets “confused” and starts attacking the body’s own tissue. Well, if gluten causes a leaky gut, and a leaky gut allows large particles to pass into the bloodstream, thereby triggering the immune system and eventually leading the immune system to attack the body's own healthy tissue, then we can say that, in a way, gluten triggers autoimmune conditions. I sucked at mathematical reasoning in college, but I do remember this much: If A --> B, and if B --> C, then A --> C. Yes! Gluten! Colonel Mustard in the conservatory with a candlestick! <-- Please tell me someone reading this blog belongs to a generation that remembers that game. (Y'know, back when games had boards, instead of screens and handheld doohickeys.)

I talked a little about this in the previous post, but it’s worth spending more time on. You can see from my handy-dandy disclaimer at the bottom of this post that I am not a doctor (nor do I play one on TV). That being said, I do not hesitate to say that anyone suffering from an autoimmune condition owes it to themselves to try a gluten-free diet. (Preferably one loaded with nutrient-dense, whole, real foods and not filled with fake, processed gluten-free foods that might actually make things worse.) It just might be the best thing they’ve ever done. I won’t bore you with tons of links, but if you’re interested in learning more about this, feel free to contact me or check out the testimonial & success story sections on Robb Wolf’s site or Mark’s Daily Apple. You will find many, many people who’ve reversed or put into remission their autoimmune conditions with nothing more than a change in diet. (I’m not allowed to say “cured,” but I would if I could.)

Remember: here’s how it works. If some of the “stuff” that slips through the leaky gut has parts that resemble parts of a normal, healthy body, the immune system will go after the “stuff” and the normal body parts. This is why anyone with an autoimmune condition must, must heal their gut. (There are other dietary and lifestyle factors that will help as well, but healing the gut is absolutely key, and avoiding gluten is the first and most important step. We'll talk about other ways to heal a leaky gut in the next post.)

What else does a gluten-induced leaky gut lead to? An easier question to answer would be what doesn’t it lead to. ‘Cuz let’s think about it: remember way back to when we talked about the potential effects of low stomach acid? Well, low stomach acid is just one form of compromised digestive function. If the small intestine is the main site of nutrient breakdown and absorption, then a leaky gut might be an even more serious compromise. If the gut is leaky, then we’re not breaking down and absorbing nutrients, and that can lead to darn near every health issue you can think of. Not digesting proteins and breaking them down into the amino acids tryptophan, phenylalanine, and tyrosine? Good luck making serotonin, dopamine, epinephrine, and thyroid hormone. Deficiencies or imbalances in these neurotransmitters and hormones can lead to fatigue, depression, anxiety, addictive tendencies, and other mood disturbances. (Not to mention that gluten can have a direct effect on autoimmune destruction of the thyroid gland. And if you happen to know anyone with a sluggish thyroid, then you know it's a giant barrel of laughs. One bit of fun after the next. <--NOT.)

There’s a reason we all love pizza: 
bread & cheese – two addictive substances in one!
And here’s something really interesting about the effect of a leaky gut on mood and psychology: there are peptides (small protein chains) called gluteomorphins and casomorphins that result from the incomplete breakdown products of gluten grains and dairy, respectively. (“Gluteo” coming from gluten, and “caso” coming from the casein protein in dairy.) If you think these sound like “morphine,” you’re right. These are compounds that interact with the opioid receptors in the brain (our pleasure centers), and this is partly why some people are straight-up addicted to grains and dairy—because they literally have a drug-like effect on them and make them feel so damn good. So think about it: with a gluten-induced leaky gut, we have a psychological double whammy. First, the leaky gut prevents us from absorbing the nutrients we need to build proper neurotransmitters (chemical messengers that regulate mood and emotions, among a ton of other functions). And second, the gluten itself gets broken down into a substance with psychoactive properties. (Meaning it messes with our heads.)

If you happen to have a “picky eater” child in your life, chances are he or she just looooves bread. Grilled cheese sandwiches are probably a favorite, because they get the best of both worlds there. They’re also probably kids whose moms say things like, “Oh, Tommy doesn’t eat anything but bread and crackers,” or, “Little Katie just loves hot dog rolls.” Yeah, um, there’s a reason for that. Those things are addictive. These kids also likely have serious behavioral and/or emotional issues. In fact, Dr. Natasha Campbell McBride created something called the GAPS Diet – short for Gut and Psychology Syndrome. That’s right: GUT and PSYCHOLOGY. She reversed her son’s autism with the intensive gut-healing protocol she now shares with the world. Long story short: when the gut is permeable, those undigested gluteomorphins and casomorphins pass through and mess with the body and brain in a major way. (Think about it: if you were under the effects of a pseudo-morphine most of your life, would you be able to communicate with people, learn, and interact with the world like everyone else? NO.) When you learn about the reasoning behind Dr. Campbell McBride's protocol, it makes total sense that children with severely compromised intestinal function experience the kind of crippling emotional/psychological and physical effects associated with conditions all along the autism spectrum, to include ADD/ADHD, dyspraxia, oppositional defiant disorder, sensory processing disorder, and others. (This is why kids on the spectrum often improve on a gluten-free/casein-free diet. Not always, but often.) And this is not new information. Specialists on spectrum disorders have long recognized that severe gastrointestinal problems and spectrum conditions frequently go hand-in-hand. (Without getting too graphic here, these kids typically have a lot of trouble in the bathroom. Severe constipation and/or diarrhea...some kids only have one, some have both, but many kids on the spectrum have at least some kind of bowel dysfunction.) We know that correlation does not mean causation, but in this case, it’s hard to think a leaky gut is not causative, or is at least not part of the cause.

This doesn’t apply only to children. How about adults with depression, anxiety, bipolar disorder, schizophrenia, ADD, etc.? The same thing holds: the gut must be addressed. This is known as the gut-brain axis. Perhaps this is a bold statement, but in my personal opinion, any psychiatrist or psychologist who doesn’t look into a patient’s diet or dig deeper into other health concerns they might have that relate to a leaky gut is doing a terrible disservice to the patient. I’m not saying that diet and a leaky gut are the only causes of psychological disturbances (‘cuz I know darn well they’re not), but in cases where there’s no identifiable “trigger” for someone’s behavior, it would be tragic if they were not helped and were relegated to a lifetime of ineffective pharmaceuticals because of a failure on the part of the counselor to look into the physiology as it affects the psychology [/end rant].  In fact, according to Dr. Peter Osborne, “Extraintestinal manifestations of gluten intolerance are a major cause of missed diagnosis in developed nations worldwide.” In other words, gluten sensitivity affects the body in places far removed from the intestines. There’s no reason to suspect the brain (and thus, our mood, attention span, mental outlook, ability to focus, etc.) is not also affected.

Depression, anxiety, or irrational anger? Difficulty dealing with everyday life? 
You owe it to yourself to look into gluten sensitivity.

What else can a leaky gut cause? How about acne, eczema, psoriasis, or other skin issues? Same thing: the body is having a kind of “allergic” or inflammatory reaction to foreign particles inside the bloodstream, and the battle is being waged via the skin. (This is known as “the gut skin axis.”) When it comes to rheumatoid arthritis, we have what they call the gut-joint axis, and researchers are well aware that dietary modifications can influence this debilitating condition. (If you’re science-minded and interested in the nitty gritty of this stuff, this paper has an excellent explanation of the molecular mimicry involved in the pathogenesis of autoimmunity. It’s about RA, but the mechanism they explain is what underlies all autoimmunity. Loren Cordain is one of the authors, for the Paleo folk among you.)

So, yeah: if it’s a part of your body, there’s probably a recognized link to the gut, and a published paper somewhere about the axis between the gut and that body part. (“Axis of Evil” was already taken, so I guess we’ll call it “Axis of Gut Dysfunction.”)

Okay, we’ve covered celiac disease and non-celiac gluten sensitivity. What about the third category? The average Joe/Jane who has no issue they know of with gluten. This is the category that yours truly falls into. I’m not gluten-free. (Quick! Someone call the food police!) I don’t eat much of it, but I do enjoy a nice piece of warm, fresh bread now and then (with lots of butter, of course), and I don’t go out of my way to avoid it in all the niggling little places it shows up. But—for now, at least—I “get away with it.” I have none of the symptoms usually associated with NCGS. (Well, maybe one or two, but there are other factors in my lifestyle that are much more likely culprits.) Still, at some point I'll try a strict 30-day gluten-free trial just to see. Cuz, hey, you never know. And I can’t know unless I completely remove it from my diet for 30 days and then reintroduce it. And maybe it is wreaking havoc, but it’s so slight and so slow-growing that I won’t know I’ve been sensitive all along until “all of a sudden” I wake up with stiff joints one day, or muscle pain all over. But being that I don’t have any issues I’d complain about with regard to gluten, the potential for something to pop up later on has to be balanced against whatever enjoyment I might get from the occasional gluten-containing cookie, warm, flaky biscuit, or fresh croissant, if I ever make my way to France. [Hi, Tomes! =)] 

Whooo-wheee, that was a long post! I do hope you learned a thing or two along the way, because I believe this stuff is important. Hippocrates was right: “All disease begins in the gut.” And if we don’t have an intact and well-functioning gut, there’s just no way we can be optimally well—physically OR mentally. 

Believe it or not, there’s a lot more to the gluten equation, but I’d say that’s more than enough for now. We’re all clear, though, right? As far as this relates to digestion (which, despite all the tangents in this post, is what this series is about), gluten can cause a leaky gut, and a leaky gut can cause all the gnarly things we’ve talked about here. 

Next time, we’ll talk about how to heal a leaky gut. It’s not as hard as you might think, but it does involve more than a midnight run to Home Depot for the right wrench.

In the meantime, for an absolutely fantastic (seriously, it’s awesome) guide to foods that contain gluten, check out this free resource from Diane Sanfilippo of Balanced Bites: Gluten Free Made Easy. (There’s also a simplified version from her book Practical Paleo: Guide to Gluten.) 

For more information on the effect of gluten on physical and mental health, I recommend this book: Dangerous Grains: Why Gluten Cereal Grains May Be Hazardous To Your Health.

For the science-minded (or just plain interested laypeople) among you, this article will blow your mind. Blow. Your. Mind. The author does an especially good job of addressing the psycho-pharmacological effects of gluten. The whole article is great (as is its sequel), but here are some key lines specific to the psychological end of things (emphasis mine):

Gliadin can be broken down into various amino acid lengths or peptides. Gliadorphin is a 7 amino acid long peptide which forms when the gastrointestinal system is compromised. When digestive enzymes are insufficient to break gliadorphin down into 2-3 amino acid lengths and a compromised intestinal wall allows for the leakage of the entire 7 amino acid long fragment into the blood, glaidorphin can pass through to the brain through circumventricular organs and activate opioid receptors resulting in disrupted brain function

There have been a number of gluten exorphins identified…and many of them have been hypothesized to play a role in autism, schizophrenia, ADHD and related neurological conditions. In the same way that the celiac iceberg illustrated the illusion that intolerance to wheat is rare, it is possible, even probable, that wheat exerts pharmacological influences on everyone. What distinguishes the schizophrenic or autistic individual from the functional wheat consumer is the degree to which they are affected.

Below the tip of the “Gluten Iceberg,” we might find these opiate-like peptides to be responsible for bread’s general popularity as a “comfort food,” and our use of phrases like “I love bread,” or “this bread is to die for” to be indicative of wheat’s narcotic properties. I believe a strong argument can be made that the agricultural revolution that occurred approximately 10-12,000 years ago as we shifted from the Paleolithic into the Neolithic era was precipitated as much by environmental necessities and human ingenuity, as it was by the addictive qualities of psychoactive peptides in the grains themselves.  

And for the super-science minded among you, check out more of Dr. Fasano's work:

P.S. If you know any Doubty-McDoubtersons who think gluten-free is a ridiculous fad or some kind of nutritional crutch for rich white people with nothing better to worry about, please feel free to send them a link to this post. It might help them understand what a big deal this really is for some people. (Sorry if that “rich white people” line is a bit harsh, but I've actually heard that uttered by people who obviously don't “get it” that there are people whose GI tracts are so eff’d up that they literally have to base their travel plans around the immediate availability of restrooms.)

Continue to the next post: Healing a leaky gut.

Remember: Amy Berger, M.S., NTP, is not a physician and Tuit Nutrition, LLC, is not a medical practice. The information contained on this site is not intended to diagnose, treat, cure, or prevent any medical condition.


  1. Wow! Just Wow! I was one of those who thought, initially, that the gluten free diet was just a fad, but have since come around. I, like you, am "gluten light", but after reading this amazing post, realize I may need to cut back even more. Thank you for your insight, and the links to back up what you say.

  2. Thanks for reading! At some point I'll bite the bullet and go fully GF just to see if I notice any difference. Who knows? I might really surprise myself.

  3. I had all kinds of issues and could never tie them to diet because my "reactions" happened 1-3 days after eating gluten (or rice! yes white rice is even worse than gluten for me) and since I rarely went more than 2 days without gluten or rice, I could never figure it out. It wasn't until I went gluten free for thirty whole days and then reintroduced it that I could start to really believe that diet was the culprit. Even after reintroducing gluten, I didn't get a big reaction. And I didn't feel totally better because I still hadn't eliminated grains entirely. But it was more like, the non-sick times were better...? Does that make sense? I could tell gluten was an issue because I felt better than normal when I wasn't sick. It's amazing how quickly we acclimate to feeling crappy most of the time. Crappy becomes the new normal. I removed the gluten and suddenly, crappy wasn't normal...something closer to feeling good became the new normal. So, I highly suggest in the face of all the evidence you already know, to give it a try because maybe you are living with a crappier normal than you need to.

    1. I know...
      I'm definitely going to go 30 days GF at some point, sooner rather than later. To be honest, I have zero physical issues that I could tie to gluten. Physically, I feel fantastic. Digestion, energy levels, skin, illness/allergies -- NADA. I'm probably in the best health & shape of my life right now. (Or pretty close to it. Hard to beat the fitness I had when I was deployed.) The only thing that could possibly be connected is mild depression, but without getting too personal here in the comments, there are things that are MUCH more likely causing that.

      Still, I do intend to go GF for a while, for two reasons: 1) You never know, I might surprise myself and feel *even better* than I already do. And 2) I owe it to my clients. It's the right thing to do, and it's only fair if I'm going to recommend GF diets for some clients. Never trust a practitioner who asks you to do something they've never done or aren't willing to do themselves. I need to remind myself how difficult it can be to make changes like that, particularly when we're absolutely SURROUNDED by wheat.

      Glad you found relief with it. And I know what you mean about feeling crappy. I have family members who've felt awful for so many years, they have no idea that they *don't* have to feel that way. That's just their "normal" now. They wouldn't know feeling *good* if it hit them over the head.

      (And the rice thing is interesting -- usually people find white rice is pretty tolerable b/c it's had most of the antinutrients and problematic fiber removed.)