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July 26, 2019
Science

Gluten sensitivity: Do you have the DNA elements that predispose you to it?

People with gluten sensitivity often have genetic mutations (changes in DNA) that modify the way their immune system reacts to gluten.
By
Tomohiro Takano

This article discusses the plant protein gluten, how it interacts with your body, and how your DNA might influence your ability to process gluten. In the article, we will learn not only what gluten is, but also hypotheses on why some people develop gluten intolerance. Interestingly, the answer may be within your DNA.

Further, we will take a look at the research that has been done relating DNA to gluten sensitivity, and we will discuss some common misconceptions about gluten and DNA testing. Then, we will take a quick look at where the research is headed. But first, let’s talk about gluten. Everyone else seems to be.


Why is everyone talking about Gluten?

You’ve probably heard of gluten-free diets, gluten intolerance, and other conditions related to the mysterious substance “gluten”. If you have Celiac’s disease, you are well aware of gluten’s effects on your body. Other people may have a minor gluten intolerance, in which gluten causes inflammation or an upset stomach. However, many people have no issues with gluten. How can this be?


Scientists have found that your DNA plays a part in your ability to handle gluten. More so, a simple DNA test can search for genetic variants that might influence your sensitivity to gluten.


But what is gluten? Why does it only affect some people? And, if you are sensitive to gluten, how would you know? More importantly, what can you actually do about it? Keep reading to learn more.


The role of gluten and its purpose in the body

All plants and animals create proteins, and each protein has a specific function within the cells of an organism. DNA, the molecule which stores genetic information, is mainly storing the information to create these proteins.

Gluten is found in many grains, such as wheat, barley and rye.

Gluten is a general term for a number of proteins found within the starch-storing cells of grains such as wheat, rye, barley, and oats. Within plant cells, these proteins act to help store the starch products of the cell. However, these proteins also interact with our cells when we ingest foods like wheat and barley. Some people have no problem processing gluten, while other people experience an immune reaction to the proteins.

Like other protein sources, gluten is composed of amino acids. Amino acids are the primary building blocks of all proteins. People who can easily digest gluten can break the proteins down into these building blocks, and then their body can use these amino acids to produce new proteins for building muscle, maintaining cells, or as protein enzymes used in digestion. However, some people’s immune systems will create antibodies for gluten and cause swelling, inflammation, and general discomfort.


So the question is: How can we analyze our DNA to understand more about our gluten tolerance?


How does DNA influence your ability to metabolize gluten?

You can consider your DNA a “blueprint” for how your body builds itself, maintains health, and interacts with your environment. In terms of digesting glucose, your DNA initiates a number of processes meant to help digest foods. Your DNA also establishes the basis of your immune system, which sometimes responds to gluten and creates gluten intolerance. While most people have an ability to digest gluten (even those with Celiac disease, an autoimmune disease), people with an intolerance of gluten often have genetic mutations which change the way their immune system reacts to the presence of gluten.


In a study of over 1000 Mexican Americans, several genes were found to contribute to and pose as a risk factor for an immune response to gluten. Two genes specifically, HLA-DR and BTNL2, were found to be positively associated with the production of gluten antibodies. Both genes function within the immune system and contribute to the process of your immune system identifying new pathogens. In fact, within this small population, the researchers found that there are several SNPs commonly associated with Celiac disease and NCGS (non-Celiac gluten sensitivity). Unfortunately for people with these SNPs, gluten is falsely identified as an invading pathogen and their immune system responds by inflaming and disturbing the intestines, stomach, and other parts of the digestive tract.  


If you suspect that you may be gluten sensitive, have food allergies, or other health concerns, you should see your health care provider and discuss switching to a gluten-free diet. Also, genetic testing or simply getting a blood test can help you understand if gluten intolerance is causing your upset stomach.


Alessio Fasano, MD, Director of the Center for Celiac Research at Massachusetts General Hospital in Boston, says that while gluten intolerance typically affects the small intestine and causes abdominal pain, symptoms can arise anywhere in the body -- especially if partially digested gluten gets circulated around our body in the bloodstream, and our immune system responds by attacking it in our tissues and organs. Symptoms include weight loss, joint pain, anemia, skin rashes, headache and depression.


Common questions about your DNA results

After analyzing your raw DNA data for your predisposition to gluten sensitivity, people often have similar questions about their test results. Below are answers to some of the most commonly asked questions.

The results say I have a high gluten intolerance, but I eat a lot of bread and I’m fine. Why is this?

The results from a DNA test will only tell you whether or not you have the SNPs commonly associated with gluten intolerance. Unfortunately, gluten intolerance is not a single-gene trait, nor is it a straightforward process. Though 95% of people with Celiac disease have at least 1 of these SNPs, not everyone with these SNPs will develop Celiac disease or gluten sensitivity. Both of these conditions are related to the immune system. However, the immune system is a highly adaptable system which can react unpredictably to different environmental conditions. But, knowing you have an increased risk can help you identify and minimize your risk of developing Celiac disease or a sensitivity to gluten.

Bread on bread on bread!

People have been eating gluten forever, why does this matter now?

This is largely a misconception. In terms of human evolution, humans have only been exposed to gluten for a short time. Humans have been evolving for millions of years, and our ability to digest foods is based on what our ancestors ate. The advent of modern agriculture happened around 10,000 years ago, which is less than 1% of the time modern humans have been separated from the other great apes. Further, many human populations were never exposed to gluten until the modern era. Gluten, which found in wheat, barley, and rye, was historically only a component of the European diet. Thus, the general population in other parts of the world are just now experiencing gluten and its side effects for the first time. Your genetics may provide insights on your personal ability to handle gluten within your diet.

Further, modern food processing techniques have been blamed for gluten sensitivity. While more research needs to be done, there is a theory that processed gluten is too concentrated. Switching to a whole-food, plant-based diet with plenty of variety will allow you to avoid these chemicals and processing techniques.


Looking ahead

Researchers have barely scratched the surface on the science behind gluten intolerance. In fact, the study presented above is a great start, but only identified SNPs within a small population from a specific ethnic background. Future research needs to focus on larger populations and the specific molecular mechanisms behind immune reactions to gluten and other food allergens.


For example, researchers may find that gluten intolerance is limited to specific populations. Populations in Europe have been eating large amounts of grains for thousands of years, but these cereals are just recently being added to the diets of other regions. The Mexican American population has historically survived without grains, having a base diet of squash, corn, and beans. None of these foods have gluten, which may be why this population experiences higher rates of gluten sensitivity. Many Asian countries are also starting to replace their base of rice with more gluten-laden products, and also may experience higher levels of gluten sensitivity.


Find out what your DNA says

Until researchers fully understand gluten and gluten sensitivities, there is still a lot your DNA can tell you about your ability to handle gluten. Certain SNPs predispose you to gluten intolerance, generally by affecting the way your immune system reacts to gluten. Check Genomelink now to find out your genetic predisposition for sensitivity to gluten!

Sample gluten sensitivity report on Genomelink
A sample report of Gluten Sensitivity on Genomelink

Did you get 23andMe, AncestryDNA, or MyHeritage results back?
Upload your raw DNA data to access 25+ traits for FREE at Genomelink!
Tomohiro Takano
Tomohiro Takano
Co-Founder and CEO
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