Atrophic gastritis (AG), also called metaplastic atrophic gastritis (MAG), is a chronic (long-lasting) inflammation of the stomach lining, which leads to the thinning and loss of protective cells that help with digestion in the stomach. AG is a precancerous condition that increases your risk of gastric (stomach) cancer.
This condition is often caused by a Helicobacter pylori (H. pylori) bacterial infection or an autoimmune reaction that occurs when your immune system attacks the cells in your stomach lining.
Researchers estimate that about 2% of people experience atrophic gastritis (AG). Experts suspect the number may be higher because symptoms can often go unnoticed or are mistaken for another condition. The condition’s cause defines the two types of AG.
Autoimmune
In autoimmune metaplastic atrophic gastritis (AMAG), the body produces antibodies against specialized cells called parietal cells in the stomach lining. Your body mistakenly attacks and destroys your parietal cells as though they were invaders. This attack means you produce less of the acids and enzymes that help with digestion. AMAG is a genetically inherited condition.
Environmental
The other subtype is environmental metaplastic atrophic gastritis (EMAG), which is caused by H. pylori infection. About 50% of people in the U.S. get H. pylori by age 60. H. pylori is more common among Black, Hispanic, and Asian people than other groups, and EMAG may be slightly more prevalent in people assigned male at birth.
Atrophic gastritis can be asymptomatic, meaning you might not experience symptoms. The most common symptom is anemia. Anemia occurs when you don’t have enough healthy red blood cells to carry oxygen throughout your body. This may happen due to bleeding from your stomach lining, reduced stomach acid production, increased hormonal regulation of iron, or the use of your iron by H. pylori.
Anemia can cause symptoms such as:
- Headaches
- Heart palpitations
- Irritability
- Loss of appetite
- Numbness and tingling in the hands and feet
- Trouble concentrating
- Shortness of breath with exertion
- Fatigue
Without treatment, you may develop more advanced symptoms of atrophic gastritis. These symptoms are rare and aren’t always specific to AG:
The most common cause of AG is an infection with H. pylori. About 30-50% of people in the U.S. get an H. pylori infection at some point in their lives.
In most cases, exposure to H. pylori occurs in childhood, but the infection doesn’t cause any noticeable symptoms. This infection attacks your stomach lining and causes inflammation. It also destroys the cells that produce substances to protect your stomach lining and help digestion.
The second most common cause is an autoimmune reaction to parietal cells. An autoimmune reaction occurs when the immune system mistakenly produces antibodies to destroy these cells.
Your parietal cells are responsible for secreting acids that help with food digestion and mineral absorption and for controlling the buildup of harmful bacteria. Gastritis can occur with damage to the parietal cells.
Risk Factors
A research review examined several studies on risk factors for AG. The most significant risk factor is H. pylori infection. In particular, two genes in the bacterium can affect the infection severity. If the bacteria are positive for these genes, cagA or VacA, you may have a much higher risk of AG.
Other factors that may increase your risk:
- Being assigned male at birth
- Being over age 60
- A precancerous condition called intestinal metaplasia (IM)
- Eating a diet high in salt
AG doesn’t always cause symptoms, so it’s difficult to know when to seek care from a healthcare provider.
People often receive a diagnosis after undergoing an endoscopy, a procedure that uses a thin tube attached to a small camera to check for changes in the organs and stomach lining. If your provider suspects AG, they may also recommend a biopsy to confirm the diagnosis.
Your healthcare provider, usually a gastroenterologist—a medical doctor specializing in digestive conditions, may also order blood tests to determine the severity of your condition. These tests will likely test for digestive enzymes, stomach acid production, H. pylori, and parietal cell antibodies.
Treatment plans will often depend on the underlying cause of your condition—whether that’s an H. pylori infection or an autoimmune reaction.
If you test positive for an H. pylori infection, the main treatment involves healing the infection. A doctor may prescribe a round of antibiotics for 10 to 14 days. The kind of antibiotics your healthcare provider prescribes depends on the strain of H. pylori.
Your healthcare provider will check your blood after treatment to make sure the infection is gone. In some cases, getting rid of your infection may reverse the damage to your stomach lining. Your provider may also offer you a proton pump inhibitor (PPI) if you’re experiencing stomach symptoms.
If you test negative for an H. pylori infection, indicating autoimmune gastritis, there’s no specific treatment. Your healthcare provider will determine a treatment plan based on the kind of antibodies you have and the level of inflammation. They may recommend vitamin B12 supplementation. They may also want to do regular endoscopies to check for changes.
Preventing AG isn’t straightforward. Exposure to H. pylori often happens in childhood and goes undetected. It’s also unknown how exactly H. pylori spreads, adding to the challenge of prevention. Experts believe that you get H. pylori by ingesting contaminated water or food.
Try to practice good hand hygiene to prevent infection, but remember that many people have already contracted the infection at an early age.
Your diet may play a role. One 2017 study found that a high salt intake was associated with an increased risk of AG. It may help to decrease your sodium intake.
AG is often found with or progresses to another precancerous condition called intestinal metaplasia (IM). In IM, the cells of your stomach lining are replaced by cells normally found in the lining of your intestines. This can happen when your stomach mucosa (lining) is damaged by H. pylori or an autoimmune reaction, and your body repairs the damage by replacing the cells with the wrong kind of cells.
IM does not cause symptoms. Having IM increases your risk of gastric cancer further because it causes more changes in your stomach lining than AG.
You may also develop other conditions related to atrophic gastritis, including:
- Achlorhydria: Lack of stomach acid production
- Chronic iron deficiency anemia: Anemia due to a lack of iron absorption in the blood
- Macrocytic anemia: Anemia due to abnormal red blood cells from an autoimmune condition
- Gastric or peptic ulcers: Sores in your stomach lining or the first part of your small intestine.
- Hemorrhagic gastritis: Bleeding of the stomach lining
- Gastric adenocarcinoma: Gastric cancer
- Rare cancers: Mucosa-associated lymphoid tissue (MALT) and gastric carcinoid tumor, cancers that affect the stomach
If you’re undergoing treatment for an H. pylori infection, it’s a good idea to continue with treatment until your healthcare provider determines your infection has cleared. You may need to undergo several rounds of antibiotics to get rid of your infection.
It’s important to keep your appointments if a healthcare provider recommends endoscopies. If there are areas of concern or changes to an advanced precancerous state, you may need to have those areas biopsied.
Your healthcare provider may prescribe vitamin B12 supplementation to replenish your low vitamin level. Iron deficiency is a common development of AG, so you may also need an iron supplement.
