What is Helicobacter pylori?Helicobacter pylori (H. pylori) is the name of a bacteria that can cause peptic ulcers. It can infect the stomach lining, dissolving the mucus film that protects it from the highly acidic stomach contents. This causes a burning pain in the stomach. Helicobacter pylori is the most common human bacterial infection. Most infections occur before age five. H. pylori infection is a common cause of peptic ulcer disease in the United States. Peptic ulcer is a localized area of erosion occurring in the stomach or duodenal (the beginning of the small intestine) lining, resulting in abdominal pain, possible bleeding, and other gastrointestinal symptoms. Most people contract H. pylori at a young age and experience no symptoms. Symptoms most commonly occur in adulthood. The signs and symptoms of peptic ulcer can be constant or sporadic, and the disease course varies among individuals. If H. pylori is the cause, the symptoms will remain as long as the infection is untreated. Some people with peptic ulcers have no symptoms at all, while others may have burning pain, severe nausea, and vomiting. In the case of H. pylori-related peptic ulcer, the infection can be treated successfully with antibiotics. You can reduce your risk of H. pylori bacteria infection by following commonsense hygiene practices, such as washing your hands with soap and water prior to preparing food and after handling dirty diapers or using the bathroom. Seek immediate medical care (call 911) for serious symptoms such as severe or persistent abdominal pain, bloody stool (the blood may be red, black, or tarry in texture), or vomiting blood or black material (resembling coffee grounds).