An ulcer is a sore that develops in the stomach lining or elsewhere in that area of the digestive system. They most often occur in the duodenum, the part of the small intestine near the stomach. Ulcers tend to appear as either craters formed through erosion of the tissue or as abnormal growths of the intestinal wall. Symptoms generally start out relatively mild, as slight discomfort in the stomach. The pain gradually worsens as the ulcer grows, getting both larger and more intense. It will often be worse at night or when the sufferer hasn’t eaten. The pain may go away for a few days or even weeks, only to come right back.
It used to be—and in some circles still is—common knowledge that ulcers were caused by stress. However, while stress can exacerbate flares, the cause is more biological. Ulcers are sometimes caused by certain medications. Aspirin and other painkillers with anti-inflammatory properties can irritate the stomach lining and cause sores to develop.
However, most stomach ulcers are caused by bacteria, most frequently Heliobacter pylori. H. pylori is an infectious bacterium that takes up residence in the stomach linings of those who contract it. It is ordinarily benign, but sometimes it gets out of control, colonizing the gut and leading to ulcers. It isn’t clear why this happens in some cases but not others, but researchers have found that gut microflora, bacteria and other microbes that line the digestive tract and play a role in metabolizing foods, are also responsible for resistance to H. pylori-caused ulcers. In particular, a class of bacteria known as Clostridia seem to create an immune response toH. pylori.
In another study, researchers also found a promising vaccine for H. pylori. This is important because in addition to ulcers, H. pylori has been linked with some kinds of cancer. The bacterium stands down a tumor defense in the gut, allowing stomach cancer to develop. The vaccine, administered orally, would prevent H. pylori from getting a foothold in the patient’s body, preventing ulcers and cancer. It can be given to people who have never been infected and to people who have been treated to prevent relapse.