Intestinal metaplasia (IM) occurs when the body replaces the cells that line the upper digestive tract (including the stomach and esophagus) with cells that line the intestines. When IM happens in the stomach, it’s called gastric intestinal metaplasia; when it occurs in the esophagus, it’s called Barrett’s esophagus.
Intestinal metaplasia does not cause any symptoms by itself, but having it may increase your risk of stomach or esophageal cancer.
Genetic factors, diet, and gut bacteria can all contribute to the development of IM, but the biggest risk factor is having an infection of Helicobacter pylori (H. pylori) bacteria.
In the United States, it’s estimated that 5% of people have gastric intestinal metaplasia and 5% have Barrett’s esophagus.
Intestinal metaplasia does not generally cause symptoms. Many people don’t know they have it until a healthcare provider discovers it during an upper endoscopy (when a tube with a camera is inserted into your mouth and through your upper digestive tract).
You may have symptoms of the underlying cause of the IM, such as acid reflux damage. Acid reflux occurs when stomach acid flows back into the esophagus, which may cause an upset stomach. If acid reflux is causing your IM, you may have symptoms of an upset stomach, like bloating, frequent burping, and heartburn.
Intestinal metaplasia can develop when the cells that line your digestive tract are damaged. When your body repairs these damaged cells, it replaces them with a different type of cell normally found elsewhere in the body.
While many factors may increase the risk of changes to the lining of your upper digestive tract, Helicobacter pylori (H. pylori) infection may be the greatest risk factor.
H. pylori is a bacterium that infects nearly 50% of the population worldwide. Most people are infected during childhood, but you can become infected as an adult. An H. pylori infection generally doesn’t cause symptoms, so you may not be aware of it until it causes complications.
An H. pylori infection starts the changes in the cells lining your stomach and promotes further changes. The infection causes inflammation, setting off a cascade of genetic changes that can cause intestinal metaplasia and may eventually lead to cancer.
Other Risk Factors
Other risk factors for intestinal metaplasia include:
- Autoimmune gastritis: This condition may increase your stomach acidity and lead to further cell damage.
- Genetic factors: If you have a first-degree relative with gastric cancer, it increases your risk of IM.
- Smoking: Smoking tobacco may double your risk of having abnormal cells in the lining of the stomach and esophagus.
- Acid reflux: In people who test positive for H. pylori, acid reflux or gastroesophageal reflux disease (GERD) has been shown to promote cell changes and IM.
- Diet: A high-salt diet may increase your risk.
- The makeup of your gut bacteria: While your gut microbiome (all the microorganisms that live in your gut) may contain bacteria that protect against H. pylori, it might also contain bacteria that contribute to the harmful effects of H. pylori.
Intestinal metaplasia is usually discovered by coincidence during an upper endoscopy performed to diagnose or monitor digestive issues you are having.
During an upper endoscopy, a healthcare provider inserts a lighted tube with a camera on the end down your throat and into the upper sections of your digestive tract. The provider can look inside and take a biopsy (a sample of your tract lining). When investigating the biopsy, they may find cells that reveal you have IM.
In the U.S., there are no standard guidelines for IM screening. That means a healthcare provider likely won’t recommend you undergo an upper endoscopy solely to look for IM.
There is currently no standard treatment for intestinal metaplasia.
If you have IM, it’s recommended you get tested for H. pylori. If you test positive for the infection, a healthcare provider will likely prescribe antibiotics to treat it. The main management method is treating the underlying cause of the IM to prevent complications.
Researchers have studied the effectiveness of endoscopic surveillance (undergoing endoscopies to monitor disease) as part of IM management. Based on the findings, regular endoscopies to track your IM may be helpful for some people.
If you have a family history or another risk factor for stomach cancer, your healthcare provider may suggest endoscopic surveillance. This will allow them to detect and remove any polyps or lesions sooner. It’s also recommended that people with Barrett’s esophagus (IM in the esophagus) get an endoscopy every 3-5 years.
Endoscopic surveillance is not recommended for most others because the benefits don’t outweigh the risks. These risks include perforation, which is a hole in the wall of the stomach or intestines when the endoscope is inserted or removed.
Most research on IM prevention has focused on preventing or treating H. pylori infection and examining whether it has any effect on IM or its progression to gastric cancer. The results are not clear. Some studies showed infection treatment stopped the progression of IM, but others did not show any significant change.
Intestinal metaplasia is one of the steps in a chain of genetic changes that can sometimes lead to gastric (stomach) or esophageal cancer. Studies estimate that having IM can increase your risk of gastric cancer 6-fold.
Chronic gastritis and atrophic gastritis can come before IM in this chain. Chronic gastritis is a lingering inflammation of the stomach lining. Atrophic gastritis is a chronic inflammation that leads to the loss of glands that produce enzymes and acids. Both are often caused by H. pylori and can progress to IM.
Next in the chain of genetic changes that can lead to stomach cancer is IM.
Cell damage from IM can lead to further DNA damage, causing enlarged cells. These abnormal cells in the stomach are referred to as gastric dysplasia. This may eventually develop into gastric adenocarcinoma, a type of stomach cancer.
IM may lead to cancer because it can prevent you from having enough of the necessary cells that protect the lining of your stomach.
Once you’re diagnosed with intestinal metaplasia, you should follow up with your healthcare provider. Regardless of what management plan your provider gives you, they will likely want to monitor you to ensure your IM does not progress into cancer. It’s important to keep your appointments and follow up with your healthcare provider.
