How Gluten Causes Celiac Disease


When I was a kid, I was afraid of Ghosts.

I used to lay in bed paralyzed with fear, thinking they were hiding in every dark corner of my room. I eventually got over it by sleeping with the lights on.

We humans fear what we don’t know… and I was mostly just afraid of the dark.

Things weren’t much different when I was diagnosed with Celiac Disease in 2007. I knew I needed to make a drastic gluten-free change in my life but I felt paralyzed with fear. It was time to face my disease… or let it stay hidden in the dark.

I chose to turn the lights on by learning how gluten caused my disease.

And in this article, I’m going to share it with you…

Celiac Disease Triggers a War Inside Your Body

Celiac Disease is an autoimmune disease. Autoimmune diseases “arise from inappropriate immune response of the body against substances and tissues normally present in the body.”[1]

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I really like that word “inappropriate“… I agree it’s inappropriate that my immune system, which is supposed to protect me from the outside world, is actually mistaking some part of my body as an evil pathogen and attacking my healthy tissue.

Under normal conditions, the immune system is designed to protect us from bad guys (called antigens) like toxins, bacteria, viruses, cancer cells, etc. When these antigens come in contact with our body the immune system is equipped to wage war and defend our home territory.

In people with autoimmune disease, the immune system gets “confused” about what’s an antigen and what’s our own healthy body tissue, recognizing it as a threat and destroying it… it’s a tragic case of mistaken identity.

So, when people with Celiac Disease eat foods that contain gluten, their immune system is uniquely programmed to recognize it as a threat and react by damaging the tissue lining the small intestine, called villi. That’s when things get “inappropriate.” The immune system thinks it’s doing a good job keeping us safe, but it’s destroying our healthy gut lining in an all-out nuclear war.

Tiny villi lining the gut take the brunt of the attack. During normal operation, these tiny villi are responsible for absorbing nutrients from our food. But over time, these long finger-like structures get destroyed to the point of flattened out stubs.

The villi destruction looks like this:


Image source: “Celiac disease: diagnostic criteria in progress”

Do these flattened out stubs look like they can absorb nutrients and “good stuff” very well?  What about protecting you from the bad guys?

Because as it Turns Out, You’re Hollow on the Inside

That’s right… from the mouth to the anus – we humans have one long hollow tube that our body considers to be part of the “outside environment.” And when we eat food, it’s actually passing through our body on the outside, while we absorb all the good stuff and let the bad stuff pass out the other end.

The gut actually plays a critical role in protecting our body from the outside environment. It’s literally functioning similar to our skin… but on the inside of the body. As food breaks down through the process of digestion in the gut, the small intestinal barrier villi absorb the good nutrients through the cells (transcellular) and protect us from undigested food, toxins, and other bad junk from getting inside. It’s just like how our skin takes in ultraviolet light from the sun while still protecting us from the outside environment.

The absorption process is supposed to look like this:

Image Source: “Surprises from Celiac Disease”

But Celiac Disease isn’t normal circumstances. And gluten is the main reason things start to unravel with this disease…

What’s so Bad About Gluten?

Plants are so much more diabolical than I ever imagined. Did you know they carry weapons of mass destruction?

I’m serious… plants are concerned about their survival just like we are. They don’t want to die, which is why they have defense mechanisms to protect them, like toxic chemicals that should deter any living being from eating them.

Virtually all cereal grains contain toxic “prolamines,” which are proteins that are extremely tough for humans to digest. The human gut is not equipped to break down prolamines small enough to absorb any nutrients from them. These toxic prolamines give the plant a protection mechanism for their survival (since they can’t get up and run away).

Wheat contains the protein gluten, which harbors one of the worst prolamine offenders called gliadin. Researchers are finding many different parts of gluten are problematic, but gliadin has the most powerful toxic effects on the intestinal barrier and severely damages the gut lining… even in healthy people. As it turns out, these toxic effects are exponentially worse for people with the genetics for gluten sensitivity and Celiac Disease[2].

Let’s take a closer look at how gliadin tricks the body into declaring war on itself…

Gliadin Causes Gut Inflammation

As I said, gluten proteins are really hard for healthy humans (and many other animals) to digest. It’s the Celiac genetic predisposition that creates the conditions necessary for an all-out war in the gut. Let’s say you eat your favorite bagel for breakfast and it travels down into your stomach. Your stomach will reduce the size and structure of the food, turning it into chyme, and send it along to the small intestine to break it down further and harvest the nutrients.

In the case of gluten proteins (like gliadin), they need to be broken down by the body before they’re useful, which is difficult for us humans. As these gliadin particles bounce around in the small intestine, they start causing damage (remember, they’re toxic).

Simply having undigested gliadin particles in the small intestine causes a release of IL-8, triggering the initial gut inflammation.[3] These are the first shots fired in this war on the gut tissue…

IL-8 activates the Th1 part of the immune system (also called the “Innate Immune System”) and it’s the first layer of defense. It provides an immediate “first responder” attack on invading antigens by stimulating inflammation.

I like to think of it as the body sending ground soldiers to engage in battle and establish a perimeter against the invading enemy. The process of battling back with inflammation begins to damage the cells lining the small intestine (enterocytes).

But what happens next is the kicker…

Gliadin Sneaks Past the Intestinal Barrier

If it’s not enough that gliadin causes gut inflammation, gliadin also finds a way to get past our defenses and slip behind enemy lines. Remember that the gut is lined with cells designed to let the good guys in and keep the bad guys out. In Celiac Disease, a major breakdown happens in this defense system when gliadin starts tricking its way through the wall.

Think of your gut lining like a mesh wall, with special doors to walk through if you have the secret code. The good nutrients and other smaller particles can slip right through the mesh in the wall without a problem. But larger undigested proteins like gliadin (and other bad guys) can’t get through the wall at all.

The doors along the mesh wall are called Tight Junctions, and they’re the gateway between the gut cells (enterocytes). Tight Junctions are controlled by an intricate process of signals keeping the protective balance intact and anything passing through these doors is said to be passing between the cells (paracellular). Researchers have identified a protein called zonulin in humans. Zonulin is one of those delicate signals that control the opening and closing of the tight junctions and it’s largely responsible for preventing paracellular absorption of antigens.[4]  

How do gliadin and zonulin interact?

As it turns out, gliadin is programmed with a secret code that causes zonulin levels to increase in people with the genetic pre-disposition to Celiac Disease.[5] As zonulin levels go up, the Tight Junctions protecting the integrity of the small intestinal barrier begin to function abnormally, opening up wider… loosening the protective barrier of the gut wall. Now the gut lining starts to allow large particles into the body that aren’t supposed to be there.

And gliadin can sneak its way right through…

Here’s what that looks like on the surface of the small intestine:


Image Source: “Surprises from Celiac Disease”

When someone with Celiac Disease eats gluten, gliadin not only triggers gut inflammation, but it has a secret code that stimulates zonulin to open up the gut wall, allowing it to sneak through the doors and start infiltrating the body. At this point, gliadin can start to accumulate underneath the gut wall, assembling its forces behind enemy lines.

Gliadin Causes Leaky Gut

Remember that the immune system has already been battling gliadin outside the gut wall with an initial inflammatory process. Now, gliadin is accumulating underneath the gut wall, causing the enterocytes to release IL-15, triggering worsening inflammation inside the gut wall.

I like to think of the release of IL-15 like calling in the immune system Special Forces… sending Intraepithelial Lymphocytes (IEL’s) to the scene. These powerful IEL’s begin to damage the enterocyte cells through a more severe degree of inflammation and the war continues to get bloodier.[6]

But that’s not all…

The IEL’s can’t match the accumulation of gliadin behind enemy lines and the inflammatory process continues to get worse. The immune system sends elite soldiers with even bigger guns called “inflammatory mediators” such as TNF and IFN that contribute to more enterocyte damage.[7]

The more severely those cells are damaged, the worse the intestinal permeability gets… and soon you’re left with full-blown leaky gut syndrome.

Now gliadin (and everything else), can freely pass through the gut wall and do as it pleases…

The process looks something like this:


Image Source: “Surprises from Celiac Disease”

Leaky Gut Causes Autoimmunity

So far the immune system has been fighting gliadin with Th1 or “innate” immune system weapons. As gliadin continues to accumulate behind the gut wall, it will begin to cross-link with an enzyme called Tissue Transglutaminase (tTG) that gets released to repair damaged enterocyte cells. The cross-linking triggers a cascade of Th2 cross-reaction that wages all-out war on the enterocyte cells.

The presence of the new gliadin/tTG cross-linked compound in the body turns on the Th2 or “adaptive immune system,” which I think of like calling in secret agent snipers good at tracking, finding, and destroying the enemy.

The adaptive immune system is a powerful immune response that has the ability to coordinate much more sophisticated attacks using antibodies. Antibodies can recognize and remember specific pathogens to mount stronger attacks each time it encounters them.

Celiac Disease morphs into full-blown autoimmunity once the gut becomes leaky.[9] The more the gut leaks, the more cross-linked gliadin/tTG becomes present,  and the stronger the immune cross-reaction becomes. Autoimmunity happens when the sniper gliadin/tTG antibodies mistakenly attack the enterocyte cells, where the tTG is produced.[10]

So, in a nutshell: the ground soldiers are fighting gliadin outside the gut wall with inflammation, the special and elite forces are fighting gliadin inside the gut wall with inflammation, and the sniper antibodies are seeking out the gliadin/tTG antigens with inflammation… all three processes leading to the destruction of the enterocyte cells lining the gut wall in their own special way. Over time, these attacks get bad enough that they completely destroy the microvilli of the intestinal lining, like a war-torn city laid to waste.

The whole process leaves those finger-like villi completely flat…

In an attempt to keep it simple, gluten causes Celiac Disease like this:

Your Body is on Fire

Celiac Disease becomes a vicious autoimmune cycle when gluten remains in the diet, the gut remains leaky, and gliadin lights the body on fire with inflammation.

And the worst part?

The immune system is on red alert, waging all-out nuclear war with every weapon it has. This can cause untreated Celiac Disease to lead to the onset of even more autoimmune diseases.[11]

On the surface, the process points the finger at gluten, or more specifically gliadin. It would make sense that a strict Gluten-free diet could end the entire process and break the cycle of autoimmunity. But remember, in the last article I pointed to recent research showing only about 40% of Celiac patients fully heal on a Gluten-Free Diet?

I learned that lesson the hard way…

Following a Gluten-Free Diet isn’t the whole story… and getting rid of gluten alone doesn’t put the fire out.

In the next post of this series, I look more closely at why Celiac Disease can’t be reversed successfully without addressing the leaky gut component, and why the conventional treatment of Celiac Disease is destined to fail.

Jordan Reasoner

About Jordan Reasoner

Jordan Reasoner is a health engineer and author. He was diagnosed with celiac disease in 2007 and almost gave up hope when a gluten-free diet didn’t work. Since then, he transformed his health using the SCD Diet and started to help others naturally heal stomach problems. You can check out his story here and find him on Google+, Facebook or Twitter.

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48 thoughts on “How Gluten Causes Celiac Disease

  1. Avatar

    I am only 15 years old. I have had the worst year of my entire life this past year. when I was 10 I was diagnosed with gluten “intolerance” when my mom finally took me to the doctor after many sleepless painful nights. last year, my stomach started hurting so badly and it gets worse as each day passes. I’m talking the worst pain you can imagine. I cry at least 4 times a day the pain is so real. after being diagnosed with anxiety, lactose intolerance, IBS, depression and so much more, one doctor finally figured it out- a full blown Celiac disease. it’s so hard to not cross contaminate because my five siblings and my parents all eat gluten daily- it’s all over our house. Even after going gluten free I haven’t felt much relief. thanks for the posts they really help me 🙂

  2. Avatar

    This article is so well-written and explains the inflammatory response easily for newly diagnosed Celiacs, but also when trying to explain it to friends and family! I was diagnosed in 2010, and this would have been SO helpful to me then. The auto-immune connection is so important. Thank you for sharing.

  3. Avatar

    My husband has a hard time understanding what cross contamination is. For instance we went to a ball game and I brought my own gluten free hot dog bun. When I went to go get a hot dog I asked for only the dog not a bun. My husband said just order the hot dog as it comes and just take the meat out of the bun and put it in your own bun. He gets frustrated with me every time we go out to eat, because the restaurant has to spend extra time preparing my food special, causing delays for the people behind us in line. Etc. I nearly lost my life 4 times because of Gluten, soy, peppers, white potatoes, eggplant and corn allergies to my gut. And also contracted Cdiff. And another hard to kill parasite. my gut has a very hard time fighting off any bad invaders. I just don’t know what to do with my husband in these restaurant circumstances. And I can’t figure out why my tummy bloats up after eating rice.

  4. Avatar

    Good info. This finally explains why most meds will not fix the problems…they are targeted to the substances/responses after the gut is breached instead of in the gut. Only the scd/paleo has helped. For many who do not test positive for celiacs after following diet…it is most likely you are or at least gluten sensitive but as both my GI doc and my hematologist explained, if you get tested after being on a gf,scd,paleo diet, the immune response/inflammation has probably subsided enough so that it does not register. In order to get true test, you have to reintroduce gluten so that the response can be detected…not worth it just to get the label.

  5. Avatar

    I have many symptoms of classic celiac disease, I went to a doctor who told me to go off gluten. Than tested me after 4 weeks off gluten. I had lost 30 pounds in 2 months. My test came back negative. I’m still trying my gluten free diet completely. I eat gluten free bread and get sick. My bladder is always in pain. I have an urge to urinate all day and night.

    • Avatar

      Hi Roberta, thank you for reaching out. This type of thing is common and you really need to take a multi approach to heal once and for all. This includes diet, supplements and lifestyle changes. IF you are in need of a program, we urge you to check out our solving leaky gut program, which focus’s on all three:

  6. Avatar
    pam santos says:

    I just had another endoscopy and colonoscopy today. ..only to be told I need to follow my diet…seriously. ..I am kosher GF. I just froze….I wanted to scream. …until I ready about leaky gut 3 days ago…I mentioned it to my gastro…she just looked at me like I was crazy…now I’m looking for a new gastrinterologist

  7. Avatar

    I just came upon these celiac articles of yours. I was re-listening to 5 of the Gluten Free Summit interviews, getting ready for Dr. Tom’s event next week. I googled something and got to you. I have to thank you so much for explaining in such great detail the process of what goes on. The Gluten Summit was great, but I felt I was missing a step or two (or three!) in the process of eating gluten and the gut and exactly what happens. I haven’t been tested for Celiacs but upon recommendation of a great functional nutritionist I went gluten free 7 years ago. Huge change in my life. 20 years of seeing MD specialists and not one of them clued into the gluten factor. My son just took the Cyrex Array 3 test this week. Thank you again!

  8. Avatar

    Hi Jordan! My husband has been celiac for a long time, we’ve gone through so many different “healing” life-style diets, now on the hallelujah raw we tried GAP, PALEO, etc. We’ve been struggling with his skin issue…he will randomly get needle-prick-like sensations all through out his body, head to toe. When it was at its worst it felt like his skin was on fire. Now it has gotten a little better but those sensations still come and go weekly, daily. He’s gone through scannings, did blood/allergy tests for foods. We’ve done our best to not only do gluten free of course but dairy and grain free too (coffee too). We’re pretty sure he has leaky gut. Any info or insight from you would be gratefully appreciated! Thank you ~

  9. Avatar

    Love your light style of writing. Lots of great articles, some of which I’ve been trying to track down. Great info and easily explained.

    My site,, has great testing info for the insidious gluten sensitivity. Please share it.

    Will let you know when my book comes out; perhaps you’ll pass the word.

    Be well


  10. Avatar

    Hi, thanks for this! I was diagnosed with leaky gut 6 years ago, but never celiac until last year! Now it all makes a lot more sense, and I understand things more clearly!

  11. Avatar

    Well done Jordan!!! I am so glad that I found you guys on the net, after YEARS I am finally starting to feel like I have my life back and can start living again. — YOU ROCK!!!

  12. Avatar

    Thanks for the great article, and graphics too!

    You know I thought there was a general consensus on LGS in the paleo/whole foods community, but then I came across this article by Bee Wilder that says it doesn’t even exist. (

    She seems to suggest that the epithelium cells of the villi simply won’t allow undigested particles to pass through, even if those cells are damaged. “Therefore large undigested food particles pass through the intestines and out of the body, just like all other indigested foods, such as fibers (cellulose), indigestible sugars, etc.” She doesn’t go into it further, but one could assume that any accumulation of undigested material leaves food for bacteria, and creates toxicity and inflammation in the body. I guess I’m wondering how it is that undigested material can make it into the bloodstream, creating an immune response? She doesn’t seem to think it is. What are your thoughts?

    Also, when you say “their immune system is uniquely programmed to recognize it as a threat and react by damaging the tissue lining the small intestine, called villi,” do you mean that in the process of attacking said substance (gluten), the tissue lining (epithelium cells) get damaged OR that the immune system attacks the tissue itself, hmm why would it do that?

    • Jordan Reasoner
      Jordan Reasoner says:

      Hang in there @jme – it took me three years to figure this stuff out 🙂

      Stay tuned into the rest of my Celiac Series and I’ll share everything with you.


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