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Helicobacter Pylori and Gastric Cancer

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Helicobacter pylori is a microorganism that grows in the stomach's inner lining. Read the article below to know more about it.

Written by

Dr. Gayathri. N

Medically reviewed by

Dr. Rajesh Gulati

Published At March 2, 2023
Reviewed AtMay 7, 2024

What Is Helicobacter Pylori?

Helicobacter pylori is a spiral-shaped bacteria in the inner mucus lining of the stomach in human beings. It secretes an enzyme called urease that converts urea to ammonia, a colorless gas with a pungent smell. This gas which is present around the Helicobacter pylori bacteria, neutralizes the acid in the stomach making it more amicable for the bacteria. The helical shape around the bacteria helps it penetrate into the mucous layer, which is mostly less acidic than the space inside the stomach. These bacteria are generally resistant to the local immune response from the body. It has been present inside the stomach of humans for a long time, and infection caused by this bacteria is quite common.

The Centers for Disease Control and Prevention (CDC) estimates that approximately two third of the total population have this bacteria in the stomach, with the infection rate higher in developing countries than in developed nations. Even though this bacteria does not cause illness in most people, it presents as a significant risk factor for peptic ulcer disease. It is the major causative factor for a majority of ulcers of the stomach and the small intestine.

In 1994, the international research agency classified Helicobacter pylori as a cancer-causing bacteria. Since then, it has been accepted that colonizing the stomach with this bacteria is an important cause of gastric cancer.

What Is the Cause of This Helicobacter Pylori Bacteria?

The cause of the occurrence of helicobacter pylori include:

  • Consuming contaminated food and water.

  • Infects people during childhood.

  • The infection is more prevalent in children living in poverty and crowded conditions.

  • Poor hygiene practices like not following good handwashing practices before eating.

What Is Gastric Cancer?

  • Gastric cancer, otherwise called the cancer of the stomach, was once a single term used for all the cancers associated with the stomach. Now the researchers have divided this into two main subdivisions, namely:

    • Gastric Cardia Cancer: Cancer present at the top of the stomach, where it is present near the heart. Overall the incidence of this cancer has been on the rise in recent years.

    • Non-cardia Gastric Cancer: Cancer is present in all other areas of the stomach.

  • It is the second most common cause of death related to cancer in the world. It is more common in Asia and South America than in other countries. Overall the incidence of this cancer is declining.

What Are the Risk Factors of Gastric Cancer?

The risk factors of gastric cancer include:

  • Age: Older adults are more prone to this cancer than people of young age.

  • Sex: Men are more prone to stomach cancer than women. Some research suggests that a female hormone named estrogen helps protect the stomach from inflammation.

  • Chronic Gastritis: Inflammation of the stomach's lining for a prolonged period.

  • Food Habits: Consuming foods with high salt content, preserved foods, and not having enough fruits and vegetables.

  • Smoking: Smoking tobacco can harm the gut.

  • Hereditary: There is a higher chance of the individual getting this cancer if any family member has this condition.

  • Surgery: Once the treatment is done for ulcers, the stomach does not produce enough acid, which will lead to the production of more bacteria which could further lead to cancer.

  • Pernicious Anemia: If the individual has this anemia, the stomach cannot absorb enough vitamin B12 for the gut to stay healthy, which will lead to the production of more bacteria, eventually leading to cancer.

  • Achlorhydria: It is a condition in which the stomach cannot produce enough acid to digest the food, leading to the growth of bacteria that have a higher chance of developing cancer.

  • Stomach Polyps: These growths on the stomach lining are generally harmless, but a certain type of polyps known as adenomas can lead to cancer.

How Does Helicobacter Pylori Cause Cancer?

  • In most individuals, this bacteria would not cause any problems.in some individuals, it can cause long-lasting irritation, swelling, and pain, which have a high probability of becoming cancer.

  • The bacterium has a flagellum, a long thread-like structure that enables the bacteria to move from one place to another. Before attachment of helicobacter pylori to the inner lining of the gastric wall, the bacteria move from an area of low pH to the surface where the pH will be high and is favorable for good colonization of the bacteria, despite the efforts made by the host to get rid of the bacteria. In most individuals infected by the bacteria, there will be inflammation and immune response against Helicobacter pylori. Still, in some cases, the infection stays for a longer duration. It leads to the destruction of the glands in the stomach resulting in atrophy (cells getting destroyed) of the gastric mucosa.

  • Individuals with a low acid level show a high tendency to atrophy, which will eventually lead to a reduction in the size of the gland and level of intestinal metaplasia (transformation of cells in the intestine), which is associated with the development of cancer.

  • Researches show that the individuals infected by helicobacter pylori bacteria developed acute inflammation of gastric mucosa with infiltration of neutrophils (a type of white blood cell), and individuals who got exposed to helicobacter pylori for a long period developed hypochlorhydria (reduction in acid level in the lining of the stomach) which can either resolve on its own or can change into gastritis which will eventually lead to cancer.

What Are the Symptoms of Helicobacter Pylori?

  • Pain or burning sensation in the patient’s gut.

  • Stomach pain gets worse if the patient is not consuming any food.

  • Loss of appetite.

  • Nausea.

  • Burping very often.

  • Bloating or gas formation.

What Are the Diagnostic Tests to Detect the Presence of Helicobacter Pylori?

  • Endoscopy: This procedure comprises a thin, long, flexible tube with a lens and a light attached to it that can be inserted down the throat into the stomach to view the inner lining of the stomach. It is gone to check for any infections and to take a sample to check for any infection in the lab.

  • Blood Tests: Performing a blood test can show the presence of Helicobacter pylori infection.

  • Stool Tests: The doctor can check the poop for proteins, which can signify Helicobacter pylori infection.


Helicobacter pylori are the cause of most ulcers of the stomach. The process of stomach cancer is caused by continuous inflammation. Knowing the symptoms of stomach cancer can help diagnose the condition and treat it early. Unfortunately, the signs of stomach cancer do not present themselves earlier. So the patient needs to pay attention to the symptoms and see the doctor as soon as these symptoms appear to prevent cancer from progressing to an advanced stage. Following good food habits like consuming more fruits and vegetables helps keep the gut healthier and prevents these diseases.

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Dr. Rajesh Gulati
Dr. Rajesh Gulati

Family Physician


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