H. pylori stands for Helicobacter pylori and it is a type of bacteria that infects the stomach. It is a common bacteria that may be found throughout the world.
Most people who are infected with Helicobacter will not experience any symptoms. However, in some people, the bacteria will damage cells on the inside of the stomach. This leads to inflammation in the stomach and a condition called chronic gastritis. People with chronic gastritis may experience abdominal pain that is worse several hours after eating as well as nausea, weight loss, a bloating sensation, and vomiting. People with long-standing Helicobacter-associated chronic gastritis are at increased risk for developing ulcers in the stomach and small bowel, and stomach cancers such as adenocarcinoma and lymphoma.
Pathologists look for Helicobacter by taking small tissues samples called biopsies from the inside of the stomach. The stomach is divided into different parts and Helicobacter is typically found in a part of the stomach called the antrum. For that reason, biopsies looking for Helicobacter should always include the antrum.
Pathologists can see Helicobacter in a stomach biopsy when the tissue sample on a slide is examined under the microscope. Often pathologists will perform additional tests, such as a special stain or immunohistochemistry, to help them see the bacteria on the slide. The image above shows Helicobacter (brown) on the inner surface of the stomach.