Celiac disease, non-celiac gluten sensitivity and inflammatory bowel disease (IBD) all affect your digestive system. But how are these three conditions related? If you have celiac disease or non-celiac gluten sensitivity, does that mean your odds of also having inflammatory bowel disease are higher? And, can the gluten-free diet help your IBD symptoms even if you don’t have celiac disease?
Much of the research on how these conditions may interrelate is pretty recent, and some of it hasn’t been confirmed by large, well-designed clinical trials.
Nonetheless, a few studies and case reports indicate that people with both Crohn’s disease and ulcerative colitis (the two main forms of inflammatory bowel disease) may be more likely to test positive for antibodies to the gluten protein, regardless of whether or not they have celiac disease. And in some cases, the gluten-free diet has helped people with inflammatory bowel disease feel better , even though those people didn’t have celiac disease.
Here’s what we know (and what we don’t know) about the possible links between celiac disease, non-celiac gluten sensitivity, and inflammatory bowel disease.
Symptoms Similar in Celiac, Gluten Sensitivity, and IBD
Celiac disease occurs when your body mistakes the gluten protein in wheat, barley, and rye for a foreign invader, triggering your immune system to attack your small intestine. Symptoms of celiac disease can vary widely (there are many, including those that don’t involve your digestive system at all), but many people with celiac suffer from diarrhea or constipation, stomach pain, fatigue, and anemia.
Symptoms of non-celiac gluten sensitivity can mimic those of celiac disease—both conditions include similar types of digestive issues. Those with gluten sensitivity, though, seem to suffer from more headaches and other neurological symptoms , such as nerve damage that causes a feeling of “pins and needles” in the arms and legs, than those with celiac disease.
Finally, symptoms of inflammatory bowel disease differ depending on which specific condition you have (Crohn’s disease or ulcerative colitis). Both Crohn’s and ulcerative colitis can cause abdominal pain, cramping, severe (sometimes bloody) diarrhea, and bloat.
Telling the Difference Between Conditions
Obviously, there’s considerable overlap between the symptoms of celiac disease, non-celiac gluten sensitivity, and inflammatory bowel disease, and that can make getting an accurate diagnosis somewhat challenging.
Doctors use blood tests to screen for celiac disease (although not everyone with the condition tests positive), and confirm the diagnosis with an endoscopy and biopsy to look directly at the lining of your small intestine to see if it’s damaged.
To diagnose Crohn’s disease or ulcerative colitis, your doctor likely will perform a colonoscopy and/or an endoscopy to look for specific signs, which are different from those of celiac disease. There’s no one blood test for inflammatory bowel disease, although more general blood tests—such as one to screen for anemia—may provide some information.
Finally, there’s no accepted medical test for non-celiac gluten sensitivity (not all physicians agree that it exists). The only way to know if you have it is to follow the gluten-free diet strictly and see if you feel better. But even that’s not definitive: you may feel better because you’ve reduced or eliminated junk food from your diet along with the gluten, for example, or just the idea that you’re doing something positive for your health may help lessen your symptoms. Still, research shows that some people do, indeed, seem to react to gluten grains with symptoms that are similar to those of celiac disease, even though those people definitely don’t have celiac disease.
Possible Links Between Celiac and IBD
Some early studies found that people with celiac disease were at much higher risk—potentially as high as a 10-fold increase in risk—of also being diagnosed with either Crohn’s disease or ulcerative colitis. However, more recent research has indicated that those with IBD have rates of celiac disease that are similar to those in the general population.
Still, there does appear to be some association between the two conditions, and genetics may explain part of that association. Recent genetic research has found that celiac disease and Crohn’s disease share four genes that appear to raise risk for both conditions. In addition, researchers have identified genes that appear to raise risk both for celiac and for ulcerative colitis.
Both IBD and celiac disease are considered autoimmune diseases, which means they involve a mistaken attack by your immune system on a part of your body. Both conditions also appear to involve problematic changes in your intestinal microbiome (the bacteria that live in your large intestine), that may cause or support inflammation.
IBD and Gluten Sensitivity May Be More Commonly Related
Non-celiac gluten sensitivity may be more likely than celiac disease in people with Crohn’s disease or ulcerative colitis, several studies show.
For example, a group of doctors in Italy and the United Kingdom surveyed their inflammatory bowel disease patients and found that 28% of them believed they had gluten sensitivity , meaning their symptoms seemed to worsen when they ate gluten-containing foods. Only 6% of these people were following the gluten-free diet at the time of the survey, though. The researchers also found that so-called “self-reported non-celiac gluten sensitivity” was associated with more severe Crohn’s disease, and they called for additional studies to determine whether the gluten-free diet would help in these cases.
In a 2014 report, clinicians in Japan (where celiac disease is quite rare) screened 172 people who had inflammatory bowel disease for antibodies to gluten via blood tests and compared those people to 190 control subjects. They found that 13% of those with inflammatory bowel disease also tested positive for anti-gluten antibodies. However, only three of those people carried one of the two main celiac disease genes, and none of them had damage to their small intestines, so none of them actually had celiac disease.
Nonetheless, eight of those with inflammatory bowel disease who also tested positive for antibodies to gluten started the gluten-free diet (another eight people from the same group followed a gluten-containing diet, and served as control subjects). After six months on the gluten-free diet, those eight people had fewer symptoms—especially diarrhea—than the control subjects, the study reported. No one in either group developed celiac disease.
So Can the Gluten-Free Diet Help in IBD?
Maybe it can, even if you don’t have celiac disease. In several cases (including in the studies above), doctors have noted that the gluten-free diet improved or resolved inflammatory bowel disease symptoms, even in people who definitely didn’t have celiac disease. People with Crohn’s disease were especially likely to benefit.
For example, in a case study published in 2013, Dr. David Perlmutter (of Grain Brain fame) reported on a patient who had been diagnosed with Crohn’s disease, and who hadn’t gotten any better with normal treatments for Crohn’s. Based on blood tests that showed his body was producing antibodies to the gluten protein and to other components of wheat, barley, and rye, the man was diagnosed with non-celiac gluten sensitivity and started the gluten-free diet.
This “led after six weeks to a complete cessation of diarrhea,” the clinicians wrote. “Upon continuation of the gluten-free diet, not only did stool consistency become normal, but the patient also started gaining weight. On follow-up one year later the patient was back to a normal state and had regained more than 80% of his lost weight.” His Crohn’s disease had gone into remission on the gluten-free diet.
Researchers from the University of North Carolina found similar (if somewhat less dramatic) benefits when they queried 1,647 people with inflammatory bowel disease about whether they had tried the gluten-free diet. A total of 19% said they had tried it previously, and 8% said they were still using the diet. Overall, nearly two-thirds of those who had tried to eat gluten-free said the diet improved their digestive symptoms, and 28% reported fewer or less severe IBD flares. Plus, those who were following the diet at the time of the survey said it helped their fatigue significantly.
The researchers said it was possible that non-gluten compounds present in gluten grains (as opposed to the gluten protein itself) might cause intestinal inflammation in people with IBD, and eating gluten-free might help alleviate this inflammation (and the symptoms associated with it). They said their study “strongly suggests a potential role of this diet” in some IBD patients, but that more research is needed to determine who can benefit most.
So yes, it’s possible that the gluten-free diet may help to alleviate symptoms of inflammatory bowel disease, even in people who don’t have celiac disease. If you’re wondering whether you might benefit, talk to your doctor about trying the diet.