If you suffer from Irritable Bowel Syndrome (IBS), you may have noticed that eliminating gluten from your diet can help to reduce uncomfortable digestive symptoms. People with Celiac disease must avoid gluten because it causes significant long-term damage to their intestinal tract. However, those with IBS and other digestive disorders may not have an allergy or intolerance to gluten specifically. So why does eliminating it from the diet provide symptom relief?
Gluten vs. FODMAPs
Before we explain why the symptom relief occurs, lets go over some basics:
Gluten is a protein found in wheat, barley, and rye.
FODMAPs is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. I know, it’s a mouthful! Basically, these are several groups of small carbohydrate (sugar) molecules that are poorly digested by everyone, and can be especially bothersome for those of us with IBS. As a result, they pass through the small intestine, undigested and become a source of food for the bacteria in your colon. These bacteria then feed on the FODMAPs causing fermentation, which can lead to the uncomfortable digestive symptoms associated with IBS including bloating, gas, diarrhea, and stomach pain.
The big difference: gluten is a protein that some people have a hypersensitivity to (Celiac Disease) or an intolerance to, while FODMAPs are poorly digested carbohydrates.
IBS: Gluten-Free vs. Low FODMAP
So why do people with IBS experience symptom relief when going gluten-free? Good question! There are two main reasons:
- The 3 grains that contain gluten (wheat, barely, and rye) are also high FODMAP foods. A pretty amazing coincidence! The protein (gluten) in these grains causes digestive issues in celiac disease. In IBS, it is the specific carbohydrates (FODMAPs) in these grains that can cause symptoms.Keep in mind: people with celiac disease can’t eat ANYTHING with gluten in it. Those with IBS may be able tolerate varying amounts of foods with gluten without experiencing symptoms.
- Most gluten-containing foods have high FODMAP ingredients. If you stop eating foods like bread, pasta and cereals and start to feel less symptomatic, it can be easy to think it’s the gluten. However, with IBS it’s much more complicated than just gluten. Current IBS research shows that the low FODMAP diet leads to symptom improvement in 75% of people and that gluten may not influence IBS symptoms at all.
Monash University Study on IBS, FODMAPs and Gluten
As I mentioned, there’s an increasing body of evidence in IBS research that re-directs blame from gluten to FODMAPs. A game-changing study published by Monash University in 2013 held a trial with 37 participants (aged 24-61) who had been diagnosed with Non-celiac Gluten Sensitivity and Irritable Bowel Syndrome, but not Celiac disease. All participants ate Low FODMAP and gluten-free for 7 days. Then, they were split into three groups. Varying amounts of gluten was introduced back into their diet while all groups continued to eat Low FODMAP. They found that only 8% of participants had gluten-specific symptomatic effects from their diet. In other words, the researchers concluded that very few people were actually sensitive to gluten, and it was the level of FODMAPs that had the greatest influence over their digestive symptoms.
Take home message: In those that don’t have Celiac Disease, it is most likely NOT the gluten in grain products, but rather the FODMAPs that cause unpleasant digestive symptoms.
Will Going Gluten-Free Reduce IBS Symptoms?
Since FODMAPs and gluten are so tightly intertwined (the 3 grains that contain gluten: wheat, barley, and rye are all high in FODMAPs), it’s hard to find a way to stick to your low FODMAP diet unless you also go gluten-free. However, you don’t need to go completely gluten-free. Some low FODMAP foods like soy sauce are low FODMAP, but do contain small amounts of wheat and gluten. People have different tolerances to wheat, rye and barley so my advice is to do your best to avoid these FODMAPs and then reintroduce foods when you’re feeling symptom relief. Choosing foods that are gluten-free, may or may not be high in FODMAPs, so it’s important to read the labels .
Wishing you good gut health & wellness,
Stephanie and the Team