Bacteria & Stomach Cancer

Helicobacter pylori, or H. pylori, is a spiral-shaped bacterium that grows in the mucus layer that coats the inside of the human stomach.

To survive in the harsh, acidic environment of the stomach, H. pylori secretes an enzyme called urease, which converts the chemical urea to ammonia. The production of ammonia around H. pylori neutralizes the acidity of the stomach, making it more hospitable for the bacterium. In addition, the helical shape of H. pylori allows it to burrow into the mucus layer, which is less acidic than the inside space, or lumen, of the stomach. H. pylori can also attach to the cells that line the inner surface of the stomach.

Although immune cells that normally recognize and attack invading bacteria accumulate near sites of H. pylori infection, they are unable to reach the stomach lining. In addition, H. pylori has developed ways of interfering with local immune responses, making them ineffective in eliminating this bacterium (12).

 https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/h-pylori-fact-sheet