test test 123Dr. Asad
Helicobacter pylori, or H. pylori, is a spiral-shaped bacterium that is able to grow in the human stomach. Normally, the acidic stomach environment prevents the survival of viruses, bacteria, and other microorganisms. However, H. pylori has evolved to be uniquely suited to thrive in the harsh stomach environment. H. pylori bacteria secrete urease, a special enzyme that converts urea to ammonia. Ammonia reduces the acidity of the stomach, making it a more hospitable home for H. pylori.
The ability to survive in the stomach provides H. pylori with a useful hiding place. White blood cells that would normally recognize and attack invading bacteria are unable to cross from blood vessels into the stomach lining. Instead, the ineffective white blood cells continue to respond to the site of infection, where they die and release nutrients that feed H. pylori.
H. pylori has co-existed with humans for thousands of years. However, because scientists believed the stomach was a sterile organ, this bacterium was not discovered until the 1980s. Some other gut bacteria actually aid their human hosts in the absorption of nutrients and defense against other, more dangerous, microbes. Because H. pylori is relatively newly discovered, the complex interactions between this microbe and humans, including its risks and benefits, are still being discovered.