H. pylori is a type of bacteria that causes various digestive problems such as gastritis, ulcers, and even stomach cancer. It is known by several synonyms such as Helicobacter pylori, H. pylori bacterium, Campylobacter pylori, and Pylori bacteria. Other nicknames of this bacterium include "stomach bug," "peptic ulcer bug," and "gastric bacterium." Despite its negative effects on the human digestive system, this bacterium is also known by some as the "friend within," as it has been found to have a protective effect against some esophageal diseases. However, it is still important to treat H. pylori infections with antibiotics and other medications to avoid complications.