By Amy Burkhart MD, RD

Do you have gluten sensitivity or celiac disease? Have you removed gluten from your diet and still don’t feel 100 percent?   Here are the top 5 reasons you may not be feeling well even when gluten is out of the picture.

Gluten sneaking into the diet, either by cross-contamination or intentional ingestion, is by far the leading cause of ongoing symptoms in patients starting a gluten-free diet. Some people mistakenly assume “a little won’t hurt” as the diet can be challenging. These small amounts may be to blame for continued symptoms. Small amounts are more likely to affect someone with celiac disease than someone who has gluten sensitivity. But, some people with gluten sensitivity are sensitive to small amounts of gluten as well.

Getting gluten accidentally occurs for various reasons, such as cross-contamination from toasters, cookware, or cutting boards. It may happen due to well-meaning “gluten eating” family members who aren’t familiar with avoiding cross-contamination. Symptoms may be from hidden gluten in products, cross-contamination, or misreading or misunderstanding labels. Cross-contamination when dining out is common-decrease this risk by using my free worldwide 100% gluten-free restaurant guide. It is searchable by location.

There are several other reasons for accidental gluten ingestion, and it often requires being a bit of a detective. This is best be accomplished with the help of a dietitian or health care professional trained in gluten-free diets if the answer is not easily uncovered on your own.

Lactose intolerance symptoms and gluten symptoms can be similar

Lactose is a sugar found in milk. Lactase is an enzyme that is used to digest the sugar. The enzyme is found on the very tip of the villi of the small intestine.

Villi are finger-like projections in the intestine where absorption occurs. These villi are damaged in newly diagnosed celiac patients and possibly in gluten sensitivity. When this happens, the enzyme is “washed away” and is not there to digest the lactose (milk sugar).

This creates symptoms of painful gas, bloating, and diarrhea. Often, after some time on a gluten-free diet (it may be months), the enzyme comes back as the villi repair. Dairy products can once again be introduced into the diet.

Sometimes, however, this doesn’t happen, and patients are forced to use a lactase supplement or avoid dairy altogether. Some patients find they can tolerate products such as yogurt or kefir in which the sugar (lactose) is “predigested.”

Most doctors fail to do vitamin blood tests

Often, at the time of diagnosis people have been ill for a very long time. Due to this delay in diagnosis, many patients have a lengthy period of malabsorption of vitamins and minerals. The intestines have not been working properly under the constant barrage of gluten ingestion.

Many practitioners fail to test for common nutrient deficiencies associated with celiac disease or gluten sensitivity.

The vitamins and minerals most commonly deficient are below, along with some common symptoms seen with these deficiencies. This list is by no means comprehensive or exclusive.

Iron- Fatigue, cold intolerance (feels excessively cold with mild decreases in temperature), poor appetite, pale skin, headaches, dizziness, shortness of breath

Vitamin D- These symptoms can be nonspecific and vague: bone pain, weakness, depression, fatigue, poor concentration, and joint pain.

Folate- Fatigue, headache, anemia, palpitations, depression, difficulty concentrating, memory problems, sore tongue, gastrointestinal symptoms such as diarrhea, nausea, vomiting

Vitamin B12- Anemia, weakness, fatigue, pale skin, sore tongue, balance problems, tingling in fingers or toes, mood changes, depression

Magnesium- Fatigue, constipation, insomnia, muscle spasms or twitches, anxiety, hyperactivity, headaches

Many patients experience ongoing symptoms due to other foods they are eating.

They may have symptoms due to other food intolerances that disappear when the particular food is eliminated from the diet.

Symptoms can range from fatigue, “brain fog,” joint pains, migraines, rashes, and digestive symptoms to many others. Common problem foods are dairy, soy, eggs, nuts, nightshades, and corn, but any food can cause a particular person’s symptoms.

It requires a bit of detective work on the part of the patient and practitioner to figure out what the actual culprit or culprits are, but the results can be quite rapid and dramatic once the instigating foods are found.

In addition to specific foods, there are several other types of common intolerances:

• Oats: Oats can be cross-contaminated with gluten and cause symptoms. In addition, some celiac patients react to oats, even gluten-free oats, in a manner similar to gluten. See my article on oats and gluten for clarification.
• Fructose Malabsorption: A 2020 Study showed 18/20 participants with celiac disease on a GF diet had ongoing symptoms due to other food intolerances. Seven had fructose malabsorption,  and more than 50% had histamine intolerance.
• Histamine Intolerance– Headaches and rashes are common symptoms of histamine intolerance-an issue seen in people with digestive problems. A low histamine diet can be helpful.
• FODMAP Intolerance: Another vital cause of ongoing symptoms is FODMAP intolerance. This is common in people with celiac disease and is blamed for most gluten sensitivity cases. FODMAP intolerance creates symptoms such as bloating, gas, and diarrhea even after eliminating gluten. This is because many other foods beyond wheat contain FODMAP sugars. Information on the Low FODMAP diet is here. Talk to your doctor further about diagnosing and treating other food sensitivities.
• Sucrose Intolerance: Sucrose, aka ordinary white table sugar, causes diarrhea, gas, and bloating. It was considered rare, but new research shows it is more common than previously thought, especially in people with underlying digestive problems.

Too many bacteria in the small intestine causes problems

SIBO is an overgrowth of bacteria in the small intestine that wreaks havoc on the digestive tract and a person’s well-being.

If SIBO goes unchecked, it can cause malabsorption of nutrients in addition to symptoms such as gas, bloating, diarrhea, and discomfort. Symptoms often worsen after the ingestion of carbohydrates and can be progressive throughout the day.

Diagnosis is made by a hydrogen breath test, although some practitioners will treat based on history alone. SIBO can also commonly be the underlying cause of histamine intolerance.

Treatment varies from patient to patient but may include diet changes, probiotics, supplements, and antibiotics.

Up to 40% of people with celiac disease have symptoms after starting a gluten-free diet. The number is unknown for gluten sensitivity.

1. Accidental or intentional gluten intake: This is the most common reason
2. Lactose intolerance: This is common in the general population. In people requiring a gluten-free diet, it is  even more prevalent
3. Vitamin deficiencies: Ask your provider to check for common vitamin deficiencies- D, Iron, B12, Folate, Zinc, and Vitamin E are the most commonly low
4. Other food intolerances: These are real, and it requires some detective work to figure them out
5. SIBO: Small intestinal bacterial overgrowth can cause significant symptoms. Bring up the topic if it has not been mentioned.