Gluten sensitivity: symptoms, causes and tips for a gluten-free diet

In recent years, more and more people are choosing to avoid gluten or wheat. A gluten-free diet is no longer just for people with coeliac disease, but is increasingly seen as part of a healthy lifestyle. At the same time, more and more people are reacting to gluten or other wheat ingredients with a variety of symptoms.

In this blog post, you will learn everything you need to know about gluten sensitivity, the potential downsides of a gluten-free diet, and the healthiest gluten-free alternatives.

What exactly is gluten?

Gluten is a protein complex that is found in many types of grains such as wheat, spelt, rye and barley. It is mainly made up of the proteins gliadin and glutenin and is often referred to as "glue protein" due to its great baking properties. Its structure ensures that doughs become elastic, rise well and have an airy texture. Gluten is generally harmless for most people, but for those with coeliac disease or gluten sensitivity, consuming it can lead to health issues.

What is gluten sensitivity?

Gluten sensitivity, or non-coeliac gluten sensitivity (NCGS), describes a condition in which the body reacts with a variety of symptoms after consuming gluten - without there being an allergic (wheat allergy) or autoimmune (coeliac disease) cause. The symptoms can either affect the digestive tract (intestinal) or occur outside the digestive tract (extraintestinal) and are usually noticeable after a few hours to days (1,2).

Researchers are still faced with many questions regarding this condition. For example, not only gluten but also other wheat ingredients could be responsible for the symptoms, which is why the term non-coeliac wheat sensitivity is increasingly being used.

How common is gluten sensitivity?

Gluten sensitivity affects approximately 0.5–13% of people worldwide. Due to the lack of clear diagnostic criteria, estimates vary widely. Only a small percentage of individuals who suspect to react sensitive to gluten can actually be clinically diagnosed with the condition (3).

Various studies show that the incidence of coeliac disease and gluten sensitivity has increased significantly over the last 50 years. One possible explanation is the increased consumption of wheat (low price, easy availability, good baking properties) and changes in the properties of modern wheat varieties, which have been made more protein-rich and more resistant to pests through breeding methods. In addition, gluten is increasingly used in processed foods as a filler and additive (1). Additionally, the quicker processing of wheat flour into bread and baked goods, without the long fermentation times typical of traditional sourdough production, contributes to reduced digestibility (1,2).

Sourdough bread with a long fermentation process or bread made from ancient grains like spelt and einkorn is often easier to tolerate for those with gluten sensitivity.

Other gluten-related disorders

There is often confusion when it comes to gluten intolerance, as various diseases and terms are associated with gluten. That's why we would like to explain a few important terms in more detail:

Gluten intolerance

Gluten intolerance is often used as a broad term to describe all conditions (outlined below) triggered by the consumption of gluten. However, it is a somewhat misleading term. Food intolerances typically occur when the body struggles to properly digest certain nutrients, usually due to a lack of specific enzymes needed for their breakdown. The symptoms of food intolerance are primarily gastrointestinal and include bloating, abdominal pain, and irregular bowel movements. A common example of this is lactose intolerance.

Gluten intolerance, strictly speaking, isn’t really a thing, as symptoms of gluten sensitivity can also occur outside the digestive tract, and it is not the absence of enzymes but rather an immune system reaction that triggers the symptoms. Therefore, while "gluten intolerance" is commonly used, it doesn’t fully capture the complexity of gluten-related conditions (1).

Non-coeliac wheat sensitivity

Strongly overlaps with the clinical presentation of non-coeliac gluten sensitivity. In recent years, research into gluten sensitivity has increasingly raised doubts that gluten is the main trigger for this condition. Other possible triggers are mainly other wheat ingredients such as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols), ATIs (amylase-trypsin inhibitors) and other wheat allergens. The term wheat sensitivity is therefore increasingly used, although these substances can occur not only in wheat, but also in other (gluten-containing) grains (2).

Coeliac disease

Also known as gluten-sensitive enteropathy, coeliac disease is an autoimmune disorder in which the adaptive immune system triggers an inflammatory response in the intestinal lining upon contact with gluten. The symptoms and severity of the disease are so varied that diagnosis can be challenging, and it often goes undetected (2). Even small amounts of gluten can cause severe damage, which is why lifelong strict gluten avoidance is essential.

While the innate immune system plays a role in gluten sensitivity, coeliac disease specifically affects the adaptive immune system. The adaptive immune system is a specialized part of the immune system that targets specific pathogens and can respond more quickly and strongly upon repeated exposure. In coeliac disease, the immune system mistakenly identifies gluten as harmful, producing autoantibodies that attack the body’s own small intestine tissue. Although many symptoms of gluten sensitivity resemble those of coeliac disease, no autoantibodies are produced in gluten sensitivity (1).

Wheat allergy

Is a disease in which the immune system reacts to wheat proteins and causes symptoms such as skin reactions, breathing difficulties and gastrointestinal problems. Wheat allergy is diagnosed primarily by measuring wheat-specific IgE antibodies. There are different types and degrees of severity. However, it often occurs in children and improves over the years or disappears completely (2).

How does gluten sensitivity develop?

The exact cause of gluten sensitivity is not yet fully understood. It is suspected that it is a reaction of the innate immune system in the intestine: so-called toll-like receptors (TLRs) are more prevalent in the intestinal mucosa of affected people. These receptors have the task of recognizing harmful substances in the intestine. In the case of gluten sensitivity, the TLRs could perceive certain food components such as gluten or ATIs as a threat and thereby trigger an inflammation that damages the intestinal mucosa and causes discomfort.

At the same time, it is suspected that an already weakened intestinal mucosa could be a risk factor for gluten sensitivity. If the intestinal barrier is damaged, microorganisms and unwanted substances can more easily pass from the intestine into the bloodstream, activate immune cells and trigger inflammation.

There is also evidence of small structural changes in the intestines of people with gluten sensitivity. For example, it has been found that intestinal villi, which are important for nutrient absorption, are often slightly smaller, the number of certain defense cells (intraepithelial lymphocytes) is slightly increased, and the number of T cells, which counteract excessive reactions of the immune system, is slightly reduced. Other factors that could play a role include an unfavorable composition of the gut microbiome, genetic factors, viral infections, or existing inflammation in the body (1,4).

When considering the substances that can trigger gluten sensitivity (or wheat sensitivity), the following are particularly relevant:

• Gluten: Gluten contains a protein called gliadin, which can stimulate the production of zonulin in the body. Zonulin is a protein that increases the permeability of the intestinal mucosa and is used, for example, as a marker for leaky gut syndrome (1).
• Amylase-trypsin inhibitors : ATIs are proteins found in various gluten-containing grains. Studies have shown that they can activate the innate immune system and trigger inflammation in the gut. Modern wheat varieties in particular have significantly higher ATI levels than older varieties such as einkorn and even spelt. Although ATIs can trigger an immune response, most people do not develop symptoms after ingesting them (1,4).
• FODMAPs, especially fructans: FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) are a large group of carbohydrates that are not fully absorbed in the small intestine and are fermented by bacteria in the large intestine. While a short-term low-FODMAP diet often has a positive effect on irritable bowel syndrome patients, the effect on symptom-like gluten sensitivity is still uncertain. Since this type of diet is very restrictive and also includes the exclusion of numerous health-promoting foods, a FODMAPs diet is not recommended in the first place.
  More specifically, the wheat components fructans are suspected of triggering symptoms of gluten / wheat sensitivity - especially bloating and abdominal pain. It is important to note, however, that fructans have prebiotic properties, meaning they are beneficial for the gut microbiota and should not be categorised as inherently "bad" (2,4).

Please note that the mechanisms of action of these plant components and their relationship to gluten sensitivity are not yet fully understood, and further clinical studies are needed. Additionally, it is important to understand that one should not simply avoid all the potential triggers mentioned above entirely. Instead, an individual, symptom-oriented dietary plan is recommended. More on this later!

Symptoms of Gluten Sensitivity

The symptoms of gluten sensitivity can vary widely, making diagnosis challenging. As a result, the condition is often undiagnosed or mistaken for other conditions, such as coeliac disease or irritable bowel syndrome.

The known symptoms include (1):

• Intestinal symptoms: abdominal pain, flatulence, diarrhea, constipation, feeling of fullness, irregular bowel movements
• Extraintestinal symptoms: headaches, migraines, difficulty concentrating, chronic fatigue, joint and muscle pain, tingling or numbness in the arms or legs, eczema, anemia, depression

Gluten sensitivity can manifest in a wide variety of ways, making diagnosis challenging.

Irritable bowel syndrome or gluten sensitivity?

Digestive issues in gluten sensitivity closely resemble those of irritable bowel syndrome (IBS). Additionally, there is another overlap between these two conditions: FODMAPs can trigger symptoms of IBS and are also considered potential triggers in gluten sensitivity. The exact connection between these two conditions is not yet fully understood. However, gluten sensitivity is relatively common among IBS patients, affecting up to 30% of those with the condition (1,3).

How is gluten sensitivity diagnosed?

Unfortunately, there are currently no specific tests for gluten sensitivity. Therefore, the diagnosis is made via exclusion (1–3):

✅ No coeliac disease detected

✅ No wheat allergy detected

✅ Symptoms disappear after eliminating gluten-containing foods from the diet

The myBioma microbiome test can provide an initial indication of potential gluten sensitivity. Since individuals with gluten sensitivity often have altered gut bacteria composition, a stool sample analysis can reveal correlations based on this.

Effects of gluten on the microbiome and gut health

In recent decades, there has been increasing evidence of the possible involvement of the gut microbiome in the development and progression of gluten-related disorders such as gluten sensitivity, coeliac disease and wheat allergy. The gut microbiome, also known as intestinal flora, comprises trillions of microorganisms in the intestine, the majority of which are bacteria.

This bacterial community has a major impact on our health and can change due to an existing disease, as well as influence the development or progression of a disease. The microbiome performs important functions such as utilizing food, supporting the immune system, maintaining the barrier function of the intestinal mucosa and communicating with the central nervous system via the gut-brain axis.

In patients with gluten-associated disorders, an altered composition of the microbiome was observed compared to healthy individuals. For example, in gluten sensitivity, a reduced diversity (= variety of gut bacteria) is evident. High diversity is considered one of the most important parameters for assessing a healthy gut microbiome. In detail, an increase in the bacteria Ruminococcaceae and a decrease in Bacteroidetes and Fusobacteria was observed.

In addition, gluten sensitivity affects the intestinal mucosa, which can contribute to inflammatory processes not only in the intestines but throughout the body. An imbalance in the intestinal microbiome can contribute to this dysfunction of the intestinal mucosa, impair food utilization, and affect the way the immune system responds to gluten and other wheat ingredients (5).

As you now know, gluten sensitivity is likely due to a reaction of the innate immune system and a dysfunction of the intestinal mucosa. The microbiome, with its influence on these two factors, could therefore play a major role in the development, but possibly also in the treatment, of gluten sensitivity.

What’s also exciting is that researchers have discovered that certain bacteria can influence substances associated with gluten sensitivity:

• Zonulin: Patients with gluten sensitivity often have elevated zonulin levels. Laboratory studies have shown that certain probiotic bifidobacterium species can reduce increased intestinal permeability caused by zonulin (5).
• ATIs: There is evidence from animal studies that certain lactobacilli species (probiotic lactic acid bacteria) can mitigate negative effects of ATIs (2,5).
• Short-chain fatty acids: Certain intestinal bacteria convert fiber from our food into short-chain fatty acids such as butyrate. These support a healthy intestinal mucosa and can increase the number of T cells (immune system regulators that are often reduced in gluten sensitivity) (1).

Based on these connections, researchers are now investigating whether probiotics could play a role in the treatment of gluten-related diseases in the future. However, further studies need to be carried out to find out which types of bacteria could be used and in what quantities. If you would like to learn more about probiotics in general, this blog post might be of interest to you: Probiotics and their effects

Independent of dietary supplements, probiotic bacteria also seem to play a role in daily nutrition - for example in bread: If wheat dough is fermented for a long time in the course of a sourdough process (primarily lactobacilli and acetic acid bacteria are at work here), the inflammation-promoting gluten component gliadin is broken down and the bread becomes better tolerated by many people with gluten sensitivity (2,5).

Treatment options for gluten sensitivity

The treatment for gluten sensitivity is based on minimizing foods that contain gluten. Unlike coeliac disease, a strict gluten-free diet is not required, as moderate amounts of gluten typically do not cause issues. The tolerance limit can vary greatly from person to person. In addition, some people tolerate different foods better or worse. Testing and adjusting the diet individually based on symptoms is therefore the only valid recommendation for gluten sensitivity. A nutritionist can be a helpful support in this regard.

A strict gluten-free diet for a limited period of a few weeks may be helpful in better identifying tolerance thresholds and non-problematic foods, ultimately reducing symptoms in the long term. However, long-term elimination diets, such as a gluten-free or low-FODMAP diet, carry the risk of an imbalanced diet with potential nutrient deficiencies and malnutrition. Therefore, they should only be followed when medically necessary (3).

Gluten-free diet – tips and food alternatives

If you want to reduce your gluten intake, there are a few important points to consider. Do not replace (whole grain) wheat products exclusively with substitutes labeled "gluten-free". Although these can be a convenient and delicious alternative, they often consist of rice or corn flour, which is low in nutrients and fiber. Naturally gluten-free, nutrient- and fiber-rich foods include pseudocereals such as quinoa, buckwheat and amaranth, or gluten-free grains such as oats, millet and teff. In addition, older grains such as einkorn have less gluten and ATIs and are therefore often better tolerated by people with gluten sensitivity.

Gluten-free foods

• Grains: oats, millet, corn, rice, teff
• Pseudocereals: amaranth, buckwheat, quinoa
• Legumes such as lentils, beans, soy, chickpeas, lupins
• Flour from seeds and nuts, for example coconut, hemp, chestnuts, tiger nuts (can be excellent ingredients for gluten-free bread or cookies)
• Fruit, vegetables, dairy products, meat and fish

These grains provide a gluten-free alternative for individuals with gluten sensitivity or coeliac disease.

By the way: Oats are naturally gluten-free, but are often processed in production facilities that also process grains that contain gluten. Commercially available oat flakes can therefore contain traces of gluten. People with coeliac disease should therefore look for the "gluten-free" label (crossed grain symbol). If you are sensitive to gluten, these small amounts are usually no problem.

Old grain varieties: often better tolerated than conventional wheat

Grains such as einkorn, emmer and spelt are also part of the wheat family, but have a more "original" nutrient composition. Among other things, they are characterized by a different protein structure than conventional wheat and, due to their lower content of gliadin and ATI's, are better tolerated by some people with gluten sensitivity (1,6). Have you ever used einkorn flour for baking? You can find a delicious recipe on our blog: Flower focaccia with einkorn flour

Long rising time improves bread's digestibility

A long baking process, in which bread and baked goods are allowed to rest for several hours, helps to break down FODMAPs and gliadin. Traditional manufacturing processes, such as sourdough, can therefore make breads more digestible and are often a better option for people with gluten sensitivity (2,5,7).

Tip: Buy your bread from bakeries that value high quality and traditional manufacturing processes. If you find products such as einkorn or buckwheat bread in their range, that is often a good indication.

Let your grain germinate

It has been observed that gluten is reduced when grains are allowed to germinate. Therefore, grain sprouts or products made from sprouted grains can be a good alternative for people with gluten sensitivity (8). For example, you can soak spelt grains overnight, let them germinate in a sprouting jar for about 2 days and then mix them into bread dough. If that's too much effort for you, you can also find pre-germinated flour, sprouted bread or sprouted muesli in selected shops or bakeries. If you want to know what else makes sprouts a true superfood, read this blog post: Growing your own sprouts: nutrient bombs from the windowsill

Make sure you get enough fiber

Fiber is extremely important for a healthy gut microbiome, which plays a significant role in gluten sensitivity due to its influence on the immune system and intestinal mucosa. Unfortunately, people who avoid FODMAPs or who replace high-fiber whole wheat products exclusively with rice or corn products often experience reduced fiber intake.

A simple way to replenish your fiber levels and strengthen your gut health is with our prebiotic myBioma Balance. It is naturally gluten-free and has been formulated to be particularly well tolerated - even by people with irritable bowel symptoms.

Beware of hidden gluten in ready-made products

Gluten and wheat are added to many, often unexpected, foods and convenience products. Always check the ingredients list. Examples of hidden sources of gluten include:

• soy sauce
• seasonings
• muesli mixes and granola
• crackers and chips
• ready-made sauces and salad dressings
• candy and chocolate bars
• Beer (contains malt, a germinated and dried grain)
• Sausages and minced meat products such as meatballs and burger patties
• Soups and sauces: Not only in ready-made products, but also in restaurants, soups and sauces are often thickened with wheat flour and fat (“roux”).

Conclusion

Gluten sensitivity still raises a number of questions in research. If you think wheat products might be causing you discomfort seek medical advice first to find out what is really behind the symptoms. If you want to reduce gluten, try foods such as millet, quinoa, buckwheat, amaranth or oats and see whether you tolerate for example sourdough bread or einkorn bread better.

It is also worth actively supporting your gut health. A healthy gut microbiome can have a strong influence on the health of the intestinal mucosa and interacts with the immune system - both factors that are associated with gluten sensitivity.