Gut check: What to know about H. pylori

Published June 20, 2026

Everyone experiences gastrointestinal symptoms occasionally, whether it’s stomach pain, nausea, or diarrhea. These symptoms can have many causes from food sensitivities to viruses or bacteria.¹,²

What is H. pylori and how does it spread? 

H. pylori (Helicobacter pylori) is a common type of bacteria that can lead to a stomach infection, and the effects can worsen without treatment.¹

Many people get the infection as a child, but it’s also common in adults over age 50 in the US.³

H. pylori bacteria is thought to spread through food that is not cleaned or cooked thoroughly or through drinking water contaminated with the bacteria. It may also spread from person to person through saliva or body fluids.³

You can help prevent spreading the bacteria by washing your hands after using the bathroom and before eating and by making sure to fully cook your food. When traveling, make sure to only drink safe, clean water.³

How does H. pylori affect gut health? 

Many people have H. pylori in their gut without experiencing any symptoms. However, the bacteria can attach to the protective lining of your stomach, damaging the tissue and causing inflammation. Infection with H. pylori can lead to gastritis, peptic ulcers, and even stomach cancer.¹,³

Gastritis is inflammation of the stomach lining. Peptic ulcers are sores that can happen in your stomach or the duodenum, which is the first part of your small intestine. Over time, an ulcer can cause bleeding or even create a hole in your stomach. Your stomach may also create more acid, leading to persistent indigestion.³

What are symptoms of H. pylori infection? 

Simply having the bacteria doesn’t mean you will have symptoms. Many people don’t know they have an infection. However, when the bacteria damage your stomach lining, you can begin to have symptoms. These symptoms often persist for weeks or longer.²⁻⁴

Symptoms of H. pylori infection 

• Bloating
• Nausea
• Unexplained weight loss
• Frequent burping
• Indigestion 
• Vomiting
• Pain that gets better when you take an antacid

Symptoms of a peptic ulcer 

• Dull or burning pain in your stomach
• Pain that gets worse on an empty stomach
• Lack of appetite

How to test for H. pylori infection 

Over time, infection with H. pylori can cause stomach cancer as well. That’s why learning the cause of your stomach symptoms early is important. When you know the cause, a doctor can help you find the right treatment.³

One simple test to look for H. pylori is a breath test. H. pylori produces large amounts of an enzyme called urease. For the test, you collect a baseline sample of your breath. You drink a urea solution and wait 15 minutes. Then test again. If you have H. pylori, the urease enzyme interacts with the solution and creates a unique type of carbon dioxide that the test measures.  

A breath test is just one way to look for the presence of H. pylori. Blood tests and stool tests are other ways to check for the infection. In some cases, people have an upper endoscopy. This is a more invasive procedure that uses a small lighted scope with a camera attached to see inside your stomach.

Based on the results of your breath test, a doctor can help you find the right treatment. H. pylori infection is often treated with antibiotics. A doctor may also prescribe medications like antacids to treat symptoms from indigestion. 

Could something else be causing your digestive symptoms? 

Viruses and bacteria

Symptoms of H. pylori infection can mirror those of other conditions that affect your stomach. Bacteria, toxins, and viruses can all affect your gut health.  

Viral gastroenteritis, or the stomach flu, causes diarrhea, nausea, vomiting, stomach cramps, and fever. Noroviruses and rotaviruses are common causes of the stomach flu. Symptoms can last for up to 2 weeks.⁵

It’s easy to mistake your symptoms for a virus, when they’re actually caused by a bacteria, such as Salmonella. If your symptoms last more than a week, testing can help let you know if certain viruses or bacteria are present.⁵

Inflammatory bowel diseases

If your stomach issues persist for months or longer, that could be a sign of an inflammatory bowel disease (IBD). IBD includes Crohn’s disease and ulcerative colitis. These conditions cause inflammation and sores along your gastrointestinal (GI) tract. This happens when your immune system attacks healthy cells in your intestines or other parts of the GI tract.⁶

It’s estimated that more than 3 million people in the US have some form of IBD.7 Symptoms of these conditions often come and go as you experience flare-ups. Many people have⁶

• Chronic diarrhea
• Pain in the stomach
• Tiredness 
• Nausea
• Weight loss
• Blood in the stool

Blood tests and stool tests can help detect these conditions. These tests look for markers that signal inflammation associated with IBD.  

Getting tested can help you better understand potential causes of your stomach symptoms and help guide you toward appropriate treatment.