Final answer:
Most gastric or duodenal ulcers are related to the bacterium Helicobacter pylori, a gram-negative bacterium that can survive in the stomach's acidic environment and is linked to increased risks of ulcers and stomach cancer.
Step-by-step explanation:
In the last decade, it has been determined that most gastric or duodenal ulcers are related to the bacterium Helicobacter pylori. This gram-negative bacterium is capable of surviving in the highly acidic environment of the stomach due to its production of enzymes such as urease. These enzymes help to neutralize the stomach acid, creating a more conducive environment for the bacterium. Infection with H. pylori is linked to chronic gastritis, peptic ulcers, and has an association with an increased risk of stomach cancer. While a large portion of the population may carry the bacterium, not all will develop ulcers or cancer. However, H. pylori is present in about 80% of gastric ulcers and over 90% of duodenal ulcers, making it a significant factor in these conditions. The treatment for ulcers often involves a combination of antibiotics targeting H. pylori and medications to decrease stomach acid, aiding in healing the ulcers.