Non Celiac Gluten Sensitivity: Finally, a study on gluten sensitivity with some bite.

I have been in practice for 7 years now. By far, the most common question I have been asked by my patients is, “are you going to ask me to stop eating gluten?” My response, “have you been told you have IBS?” Patient, “yes.” Me, “then yes.”

Even my medical colleagues poke fun at my gluten crusading.  Where’s the evidence? they ask.  It can be frustrating not having any evidence other than clinical experience to fortify my conviction.  But something must be right, right? Because my patients with irritable bowel syndrome (IBS) tend to get significant results when taken off gluten AND you can’t even walk down an ordinary street in Vancouver without bumping into a Gluten Free Options Inside! sign. It’s too popular to be wrong, right?

IBS is one of those disease labels that get stuck on people who have digestive problems like chronic alternating constipation and diarrhea with or without associated bloating and pain and have been ruled out of having any other known disease. It’s called a diagnosis of exclusion. This doesn’t seem very fair to people who suffer these symptoms, but there is not much conventionally understood about the problem. Until now.

Jessica Biesiekierski and co. decided to investigate why people, who are not celiac, feel better off gluten? The American Journal of Gastroenterology published their study in 2011 poignantly entitling it, Gluten causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial. Double-Blind Randomized Placebo-Controlled is gold – music to my ears. Sounds like vindication to me.

Jessica and the other study investigators made sure none of the people they were testing had any chance of being celiac. They either antibody tested (TTG and EMA), genetically tested them, which has almost 100% confidence or performed biopsy while on a gluten diet, which also has 100% confidence in detecting celiacs.  They excluded both the celiac positive and any persons on medication or with other digestive complaints explainable by a different disease other than IBS.

The 39 study participants were asked to eat a gluten free diet for two weeks 19 of whom introduced gluten containing bread and a muffin every day for 6 weeks. Just to make sure they were eliminating certain confounds; the gluten free muffins and bread could not be distinguished from the gluten containing ones by basis of taste or texture in independent testing. They then reported on their overall gut symptoms like bloating, abdominal pain, satisfaction with stool consistency, nausea and tiredness. More objectively, blood, urine and stool samples were collected before and after the experiment and intestinal permeability was measured.

The results were revealing. 68% of the gluten group reported their symptoms were not adequately controlled, while 40% of the placebo group said the same. The scores of pain, satisfaction with stool, and tiredness were more severe in the gluten group. There was no difference with any of the biomarkers between the groups. Jessica and co. suggest their results “infer a statistically robust result, with unequivocal significant separation of the two groups.” In fact, every participant experienced worsening of their symptoms when eating gluten, especially their reporting of tiredness, which to them indicated a systemic effect of the gluten – an effect that goes beyond the gut.

The study author’s pointed out that previous research has shown gliadin (a gluten family protein) increases intestinal permeability, changes tight junction structure, causes cell death, increases oxidation of cells, and inhibits RNA and DNA synthesis. These points and others may indicate how gluten and gliadin are able to cause negative symptoms in people with IBS, but none of the biomarkers in the study were able to confirm any of these effects physiologically.  Despite that, symptoms persisted.

The conclusion – People with IBS actually have something coined Non-Celiac Gluten Sensitivity (NCGS) and we should take the effect of gluten seriously because not only can it cause gut symptoms, but has profound effects on systemic symptoms like tiredness. My own further extrapolation is that it may be implicated in a number of other disease processes that we have not elucidated yet by study, but see in clinical practice all the time.  Maybe we can also entertain the idea that a similar effect is possible through other foods?  We have some high-quality evidence to back us up now when we prescribe gluten-free diets to patients with not-otherwise-defined digestive symptoms.

Study Reference: Biesiekierski, J. et al.  Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial. Am J Gastroenterol 2011; 106:508–514; doi:10.1038/ajg.2010.487; published online 11 January 2011