Autoimmune gastritis (AIG) is just one of over 100 known autoimmune diseases that collectively impact over 24 million Americans. In general, autoimmune diseases result from a misguided immune system response. In autoimmune gastritis specifically, the immune system mistakenly attacks the top and middle portions of the stomach, which impacts the ability to digest and absorb food.
AIG is estimated to affect 2-5% of the Western population and can significantly impact the quality of life and overall health. Without treatment, patients can experience gastrointestinal distress, nutritional deficiencies, and are at a greater risk of developing gastric cancer.
All autoimmune diseases are on the rise, and research has shown that the number of Americans with antinuclear antibodies (a popular autoimmunity marker) continues to increase. While conventional medicine has limited offerings for people with autoimmunity, an integrative approach, which targets the root causes of the autoimmune process, can provide much symptom relief and prevent future complications for patients with AIG. Β
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What is Autoimmune Gastritis?
Autoimmune gastritis (AIG), also called autoimmune metaplastic atrophic gastritis or chronic autoimmune atrophic gastritis, is a specific type of atrophic gastritis that wastes away the stomach lining. Atrophic gastritis is relatively common and may affect up to 15 percent of the U.S. population.
AIG is a severe, chronic inflammatory disease that impacts the fundus (top portion) and corpus (body) of the stomach. Essentially, the immune system (via anti-parietal cell and anti-intrinsic factor antibodies) mistakenly attacks the lining of the stomach, which destroys the parietal cells of the oxyntic mucosa. When parietal cells are lost, less hydrochloric acid (HCl) is produced. With less HCl, the pH of the stomach increases, which in turn affects a personβs ability to digest food well, and to destroy potential disease-causing pathogens. Additionally, a protein called intrinsic factor, which helps the body absorb vitamin B12 is decreased.
If left untreated, iron and vitamin B12 malabsorption can result, as well as put patients at greater risk for developing gastric cancer. One study placed patients at 6 fold risk of developing gastric cancer. The increased cancer risk in AIG is related to the development of intestinal metaplasia that results from chronic inflammation of the stomach lining. Over time, normal, healthy gastric cells are replaced by abnormal cells that resemble those of the intestines. These new cells are precancerous in nature, so early diagnosis and treatment of AIG are crucial.
Like other autoimmune conditions, AIG affects more women than men, but older people also have a higher risk since it develops over time. In addition, people with other autoimmune conditions like Addison's disease, chronic spontaneous urticaria, Hashimoto's thyroiditis, and type 1 diabetes are also at greater risk.
Symptoms of Autoimmune Gastritis
People with AIG can have no symptoms at all, especially early on in the autoimmune process. But AIG can lead to serious health issues, so itβs imperative to listen closely to patient complaints and to complete a thorough history and physical examination.
Since AIG affects the hydrochloric acid-secreting parietal cells of the stomach, patients may experience the symptoms of hypochlorhydria (too little stomach acid), which include:
- Delayed gastric emptying:
- Nausea
- Vomiting
- Abdominal pain
- Poor Appetite
- Bloating
- Feeling too full
- Heartburn
- Small intestinal bacterial overgrowth, which causes the above symptoms of delayed gastric emptying and:
- Gas
- Diarrhea
- Constipation
- Fatigue
- Abdominal distension
- Intestinal infections
- Undigested food in the stool
As the autoimmune process continues, the parietal cells and intrinsic factor become more affected, so patients may begin to experience signs and symptoms of anemia and iron and vitamin B12 deficiencies, which include:
- Chest pain
- Dizziness
- Weakness
- Headaches
- Heart palpitations
- Confusion
- Nausea
- Vomiting
- Pale skin
- Rapid heart rate
- Ringing in the ears
- Tingling or numb limbs
- Shortness of breath
- Restless leg syndrome
- Extreme fatigue
What Causes Autoimmune Gastritis?
Helicobacter pylori (a bacteria) infection is the most common cause of atrophic gastritis worldwide. While H. pylori-related gastritis may not be the only cause, H. pylori infection may still be a component of AIG.
As with all autoimmune diseases, instead of attacking microbes and toxins that are potentially harmful, your immune system attacks your own healthy cells, tissues, and organs. In AIG specifically, the inappropriate immune system response causes chronic inflammation and subsequent damage to the stomach lining, but thereβs no one specific cause. Instead, as with many autoimmune diseases, environmental triggers (like H. pylori infection), and increased intestinal permeability are thought to be contributing factors.
Increased intestinal permeability (also called leaky gut) is a result of gut microbiome dysbiosis and inflammation. The barrier between the small intestine and the systemic blood supply consists of a layer of cells with tight junctions, which regulate what goes in and out of the gastrointestinal tract. Zonulin (a family of proteins) is the gatekeeper to these tight junctions, thus regulating when and how they open and close. When upregulated, zonulin increases the permeability of the small intestinal barrier, which allows large, undigested food particles, bacteria, and toxins to enter the bloodstream. In genetically susceptible individuals, this can trigger an inappropriate immune system response that leads to the development of autoimmune diseases like AIG. Β
Interestingly, gut dysbiosis and gluten (a protein in some grains) are the two main upregulators of zonulin, which means that both can be addressed with diet and lifestyle measures. While conventional medicine has a limited ability to treat autoimmune diseases effectively, integrative providers use various gut-healing therapies (like nutrition, stress management, exercise, and sleep) to target the underlying causes of dysbiosis and leaky gut, which can significantly improve quality of life, but also clinical outcomes. Β
How To Test for Autoimmune Gastritis
Diagnosis of AIG can be difficult early on as changes to the lining of the stomach can be subtle. For this reason, tissue biopsy via endoscopy is the gold standard for determining an AIG diagnosis. Other conventional diagnostic methods include checking for anti-parietal cell antibodies, a very sensitive biomarker for AIG. Other testing options may include checking the levels of anti-intrinsic factor and anti-H. pylori antibodies and evaluating for H. pylori infection as a link has been shown between H. pylori and the development of gastritis. Additionally, when AIG is suspected, patients should be evaluated for anemia related to iron and vitamin B12 deficiency, which can be accomplished with serum testing.
When evaluating the risk of gastric cancer in AIG patients, elevated serum gastrin levels, low levels of pepsinogen 1, and a low pepsinogen 1 to pepsinogen 2 ratio, along with the presence of atrophic gastritis in the top portion and the body of the stomach can indicate high cancer risk.
How to Test for Root Cause of Autoimmune Gastritis
Functional medicine labs can give practitioners more insight into whatβs driving the autoimmune process for people with suspected AIG. By investigating environmental triggers and increased intestinal permeability, practitioners can better develop a comprehensive treatment plan that combines conventional and integrative therapies.
Gluten Sensitivity Testing
Increased intestinal permeability is one trigger for autoimmunity. Gluten is an upregulator of zonulin (the gatekeeper of the intestinal barrier), but other food allergies and sensitivities can also contribute to inflammation and increased intestinal permeability. Certain foods may need to be removed from the diet to re-establish healthy gut barrier function based on test results.
Nutritional Testing
Since patients with AIG are at risk of iron and B vitamin deficiency related to interrupted digestion, evaluating nutritional status is essential. Micronutrient deficiencies can contribute to the underlying autoimmune process. The Cellular Nutrition Assay from Cell Science Systems shows micronutrient status for several nutrients and also provides personalized recommendations for patients with autoimmune disorders. Β Β
Comprehensive Stool and Intestinal Permeability Testing
The GI-MAP + Zonulin test is a stool test that measures a variety of gastrointestinal microbiota DNA using qPCR technology. It detects microbial imbalance (dysbiosis), microbes contributing to illness (like H. pylori, since this can be a trigger for AIG), and indicators of digestion, absorption, inflammation, and immune function. In addition, measuring zonulin allows us to better understand how increased intestinal permeability (leaky gut) may be contributing to the autoimmune process, which will guide the treatment of this underlying cause. Β
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Conventional Treatment for Autoimmune Gastritis
Patients with AIG are often provided with supplemental iron and vitamin B12 to help improve nutrient levels and reverse the symptoms of anemia. If H. pylori is present, treatment with a combination of clarithromycin, a proton-pump inhibitor, and amoxicillin for 14 to 21 days is usually implemented to eradicate the infection. Patients are also routinely evaluated for gastric cancer, as well as other autoimmune conditions, via serum testing and biopsy.
Additionally, conventional providers may encourage daily stress management practices and recommend the avoidance of gut irritants like smoking, alcohol, non-steroidal anti-inflammatory drugs, and spicy foods.
Functional Medicine Treatment for Autoimmune Gastritis
Complementary and integrative medicine (CIM) approaches may be used alongside conventional treatments to manage autoimmune gastritis, an autoimmune condition in which the body's immune system attacks the cells lining the stomach.
Below are some CIM treatments that have been used to manage autoimmune gastritis:
Best Nutrition for Treatment of Autoimmune Gastritis
Making nutrition-related changes is one of the most impactful strategies for improving gut health and managing autoimmune conditions, including AIG. Thereβs no specific diet for AIG, but the overall goal should be a meal pattern promoting gut health.
As weβve discussed, gluten (a protein found in wheat, barley, and rye) increases zonulin, triggering increased intestinal permeability that leads to inflammation and immune dysregulation. In addition, ultra-processed foods, food allergies, and sensitivities create inflammation and dysbiosis in the gut, which can also increase intestinal permeability and stimulate the misguided immune system response.
Specific to AIG, diets high in sodium, meat, animal fat, starchy foods, and alcohol may increase the risk of precancerous gastric lesions as well as gastric cancer. Β And patients with chronic gastritis report more gastric symptoms when they consume foods high in sugar and sodium and donβt follow routine meal times.
So, in general, a whole-foods, anti-inflammatory diet that restricts gluten, foods that youβre sensitive to, and alcohol will likely be very effective for AIG. The Mediterranean diet is one dietary pattern thatβs been found to improve various outcomes in patients with other autoimmune disorders, and itβs associated with a lower risk of gastric cancer, so itβs an excellent first option for AIG patients who are accustomed to consuming a standard Western diet, which promotes inflammation and dysbiosis.
The Mediterranean diet is rich in healthy fats (mainly olive oil), fruits, vegetables, nuts, seeds, whole grains, fish, poultry, and legumes, with little red meat, dairy, eggs, and wine. While this diet doesnβt restrict gluten or alcohol, you can easily modify it to exclude both while improving your overall gut health and getting AIG symptoms under control.
Supplements Used in The Treatment for Autoimmune Gastritis
While diet-related changes can be beneficial, several dietary supplements can work in conjunction with diet to improve symptoms and target the root causes of AIG.
Probiotics
Probiotics are bacteria that provide a multitude of health benefits. Specifically for people with autoimmunity, probiotics have been found to improve the gut environment and inflammation. Β Probiotics also help to reduce leaky gut and improve gut barrier function, which are critical underlying issues in people with autoimmunity. Β In addition, probiotics help with H. pylori eradication, which can be a trigger for AIG.
Gut Healing Nutrients
Several gut-healing nutrients may be beneficial for people with AIG. L-glutamine is an amino acid thatβs the preferred fuel for enterocytes and colonocytes. Itβs been found to decrease intestinal permeability, improve gut barrier function, and positively influence the inflammatory response. N-acetylcysteine (NAC) is another important amino acid thatβs able to regulate the tight junctions of the intestine and also reduce inflammation. Zinc and L-carnosine may also be used to reduce infection with H. pylori and prevent irritation to accelerate healing and prevent future damage.
Vitamin B12 and Iron
AIG often leads to nutrient deficiencies of iron and vitamin B12. Pernicious anemia is common in AIG patients related to the inability to absorb vitamin B12 due to the lack of intrinsic factor. Vitamin B12 deficiency also contributes to iron deficiency in AIG patients. In addition, iron deficiency can result from inadequate stomach acid and H. pylori infection. Itβs important to eradicate H. pylori, as continued infection can make oral iron less effective.
Complementary and Integrative Medicine Treatments for Autoimmune Gastritis
Outside of diet and supplements, additional complementary and integrative medicine lifestyle strategies improve quality of life and target the underlying inflammation in AIG patients.
Acupuncture for The Treatment of Autoimmune Gastritis
Acupuncture is the ancient practice from Traditional Chinese Medicine of inserting thin needles into strategic points on the body, which among other benefits, can help to lower inflammation. While research studies on acupuncture for AIG are limited, one proteomics study found the expression of certain proteins that contribute to AIG to be improved after acupuncture. The World Health Organization also recognizes acupuncture as a treatment for several inflammatory diseases, including rheumatoid arthritis, which is an autoimmune disease. Acupuncture may benefit those with AIG via modulation of the immune system with subsequent reductions in pro-inflammatory cytokines and digestive system inflammation.
Stress Reduction Techniques for The Treatment of Autoimmune Gastritis
The connection between stress and the immune system has been well-established. Unmanaged, chronic stress can lead to chronic inflammation and poor immune system function, which both contribute to and exacerbate poor gut health. Itβs important for patients with AIG to practice a daily stress management technique. Yoga and meditation techniques like deep breathing may decrease inflammatory markers in people with autoimmune diseases. Additional stress management options have been shown to help improve immune system function, including tai chi, qigong, guided imagery, and affirmations.
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Summary
Autoimmune gastritis is just one of many autoimmune diseases on the rise in Western nations today. In this condition, the immune system mistakenly destroys the cells that line the stomach, which affects a personβs ability to digest and absorb their food well. When left untreated AIG can lead to nutritional deficiencies and even gastric cancer.
Diagnosing AIG is difficult as patients may have no symptoms early on and any symptoms they do experience often mimic those of other conditions. While thereβs no one specific cause of AIG, environmental triggers and increased intestinal permeability are all contributing factors.
Conventional treatments include eradicating H. pylori, replacing missing nutrients like iron and vitamin B12, closely monitoring gastric cancer, and lifestyle changes like not smoking, avoiding spicy foods, and practicing stress reduction techniques.
Integrative practitioners can take this further by targeting root causes to re-establish healthy gut barrier function with a personalized anti-inflammatory diet, supplements like probiotics, gut-healing nutrients, acupuncture, and specific stress management techniques like yoga and meditation.