Ulcerative Colitis and Gluten

I removed gluten from my diet early on. Not because it was trendy, but because the science around a molecule called zonulin was convincing — and I could feel the difference. My Crohn's was active at the time, my gut lining was a mess, and anything that made the barrier worse was something I needed to address. That was years ago. I have been in full recovery without medication since, and gluten removal was one piece of that puzzle.

Now, working with hundreds of clients who have ulcerative colitis, I see the same pattern play out regularly. Not in everyone. Some people tolerate gluten just fine. But for those whose intestinal barrier is already damaged, gluten can quietly keep the fire going.

What Gliadin Actually Does to Your Gut Wall

Gluten is made up of two protein groups — glutenins and gliadins. When it comes to what happens at the gut lining, gliadin is the one that causes trouble. Your digestive enzymes cannot fully break it down. Large fragments survive the stomach and arrive at the intestinal wall mostly intact, and that is where things get interesting.

Dr. Alessio Fasano, one of the leading researchers in this field, discovered that gliadin triggers the release of a molecule called zonulin. Zonulin controls the tight junctions between the cells of your gut wall — the structures that decide what gets through and what stays out.

Think of your gut lining like a wooden fence. The boards are your intestinal cells. The tight junctions are the gaps between those boards. Under normal conditions, those gaps are sealed tight — only tiny, fully digested nutrients slip through. Zonulin is like someone prying those boards apart. The gaps widen. Suddenly, bacteria, undigested food particles, and toxins that should stay inside the gut start leaking into your bloodstream.

Your immune system sees those particles and does what immune systems do — it attacks. Inflammation follows. And if you already have ulcerative colitis, you just added fuel to a fire that was already burning.

This Happens in Everyone — Not Just Celiac Patients

Here is the part that most gastroenterologists skip over. The zonulin response to gliadin is not limited to people with celiac disease. Research by Drago and colleagues showed this clearly back in 2006 — gliadin increased intestinal permeability in both celiac and non-celiac gut tissue. The difference was a matter of degree, not of kind.

That finding changes the conversation. You do not need a celiac diagnosis for gliadin to be loosening your tight junctions. You do not need anti-tTG antibodies or villous atrophy. If your gut barrier is compromised — and in ulcerative colitis, it almost certainly is — then gliadin may be making it worse through a mechanism that has nothing to do with celiac disease.

So the question is not whether you have celiac. The question is whether your already-damaged gut lining can afford the additional hit.

How We Test for It in Our Practice

In our practice, we use IgG food intolerance testing to get a clearer picture of what is happening. These tests measure immunoglobulin G antibodies against specific food proteins in the blood. When your gut barrier is leaky, food proteins cross into the bloodstream in quantities that trigger an immune response. Elevated IgG levels to wheat or gluten can be a signal that those proteins are getting through.

I want to be straightforward about this — IgG testing is not a diagnosis. It does not tell you that you are allergic to gluten. What it does tell you is that your immune system is reacting to it, which in the context of a damaged gut lining is useful information. Often gluten shows up as one of the reactive foods. Sometimes it does not. We have seen both plenty of times.

The test results give us a starting point. The real confirmation comes from what happens when you remove the food and then bring it back.

The Elimination Protocol That Actually Works

If you want to know whether gluten is a problem for you, guessing will not get you there. You need a structured elimination and reintroduction.

Remove all gluten-containing grains — wheat, barley, rye, spelt — for four to six weeks. That time frame matters. Your gut lining needs weeks to start recovering, and your immune system needs time to calm down. A ten-day trial tells you almost nothing because mucosal healing is slow.

Be thorough about it. Gluten hides in sauces, seasonings, processed meats, and even some supplements. A sloppy elimination gives you sloppy results, and then you are back to guessing.

After four to six weeks, reintroduce gluten deliberately. Eat a normal portion of bread or pasta for two or three days in a row and pay close attention over the next 72 hours. Watch for changes in stool, bloating, abdominal pain, urgency, blood, fatigue — anything that shifts. If the elimination brought clear improvement and the reintroduction brings symptoms back, that is your answer. No blood test needed.

Gluten-Free Is Not a Cure

I need to be honest about something. Removing gluten did not fix my Crohn's on its own, and it will not fix your colitis on its own either. It was one factor among many — gut flora restoration, reducing processed food, managing stress, targeted supplementation. The list goes on.

And not everyone with UC needs to avoid gluten. I have worked with clients whose IgG panels came back clean for wheat, whose symptoms did not change during elimination, and for whom gluten was simply not a driver. Restricting foods unnecessarily leads to nutritional gaps and a miserable relationship with eating. That helps no one.

But if your gut lining is compromised — and the science from Fasano's work makes it clear that gliadin opens tight junctions through zonulin release — then continuing to eat gluten without at least testing your response is a missed opportunity. You are potentially keeping the fence broken while wondering why things keep getting through.

Find out whether it matters for you. Do the elimination properly. Let your body give you the data. Then decide based on what you actually experience, not on what the internet tells you to believe.