The Short Answer

Food sensitivities are common in autoimmune conditions because immune dysregulation makes your digestive system more reactive to certain foods. Testing can identify your specific triggers, allowing you to eliminate problem foods and reduce inflammation, but the right test depends on your individual needs and symptoms.

Understanding Food Sensitivities in Autoimmune Conditions

You’ve probably heard of gluten-free, dairy-free, and soy-free diets and products. These restrictions exist because certain foods trigger undesirable symptoms in many people, especially those with autoimmune conditions or chronic illness.

Food sensitivities are different from food allergies. An allergic reaction involves your immune system producing IgE antibodies, which can cause immediate, often dramatic symptoms such as swelling, hives, or difficulty breathing. A food sensitivity involves IgG antibodies or other immune responses that develop over hours or days, producing subtler symptoms like bloating, fatigue, brain fog, joint pain, or skin issues.

For people with autoimmune conditions, including those with Hashimoto’s low thyroid, the connection is direct: immune dysregulation in the gut makes the intestinal lining more permeable and reactive. This means your body may mount an inflammatory response to foods it would normally tolerate.

Why Autoimmune Patients React to More Foods

When your immune system is already activated by autoimmunity, your digestive tract becomes hypersensitive. The cells lining your intestines are under constant immune surveillance, and certain proteins in food can trigger a reaction.

Common trigger foods for autoimmune patients include:

Gluten (especially in those with Hashimoto’s low thyroid)

Dairy products

Eggs

Soy

Corn

Nightshade vegetables (tomatoes, peppers, eggplant)

Legumes

Processed seed oils

This doesn’t mean you’re allergic to all of these. It means your individual immune system may react to one, several, or none of them. The only way to know is through testing and elimination trials.

Types of Food Sensitivity Tests

IgG Food Sensitivity Testing

This blood test measures IgG antibodies to specific foods. Your immune system produces IgG antibodies when it’s repeatedly exposed to a food protein. High IgG levels suggest your body is mounting an inflammatory response to that food.

IgG testing is useful because it identifies foods you regularly eat that may be causing low-grade inflammation. Many autoimmune patients find that removing high-IgG foods reduces flare frequency and symptom severity.

Elimination and Reintroduction Diets

This is the gold standard for identifying food sensitivities. You eliminate suspected trigger foods for 3-4 weeks, then reintroduce them one at a time while tracking symptoms.

The advantage: you get real-world data about which foods actually affect you, rather than relying on test results alone. Many autoimmune patients discover that their sensitivity to a food is dose-dependent; they can tolerate small amounts but react to larger quantities.

Microbiome Testing

Your gut bacteria play a significant role in immune tolerance. When dysbiosis (imbalanced bacteria) is present, you’re more likely to develop food sensitivities. Microbiome testing identifies which bacterial species are missing or overabundant, guiding targeted supplementation and dietary changes.

Creating Your Personalized Food Plan

At RedRiver, we don’t believe in one-size-fits-all elimination diets. Instead, we use testing results as a starting point for personalized removal and reintroduction.

Here’s how the process typically works:

1. Test or track. Either through IgG testing or a symptom diary, identify likely trigger foods.

2. Eliminate strategically. Remove only the foods most likely to be problematic, not everything at once. A completely restrictive diet can worsen nutritional status and anxiety.

3. Support healing. Strengthen your intestinal barrier with bone broth, L-glutamine, and omega-3 fatty acids.

4. Reintroduce systematically. After 3-4 weeks, add foods back one at a time, waiting 5-7 days between each to observe reactions.

5. Adjust based on response. Your tolerance may change as your immune system calms and your gut heals. Foods you’re sensitive to now may be reintroduced later.

This approach prevents the frustration of eliminating foods you don’t actually need to avoid, while ensuring you identify your genuine triggers.

Beyond Testing: Addressing Root Causes

Food sensitivities are symptoms of immune dysregulation, not the root problem. Simply avoiding trigger foods helps reduce inflammation, but doesn’t address why your immune system is hyperactive in the first place.

At RedRiver, we combine food sensitivity testing with evaluation of:

Gut barrier integrity and dysbiosis

Chronic infections (viral reactivation, bacterial overgrowth)

Stress and sleep patterns

Nutritional deficiencies

Environmental toxin exposure

When you address these underlying drivers, food tolerances often improve naturally.