An ulcer is a lesion of a mucous membrane or the skin that causes tissue to die away or degrade. There are many potential types of ulcers, especially in the digestive tract and those that appear on other areas like the feet, legs, or in the mouth. The connection between bacteria and ulcers relates to the types of ulcers found in the gut, usually in the stomach or duodenum, that may also be called peptic ulcers. Presence of bacteria in other types of ulcers can be a concern as well.
For a long time, it was believed that ulcers in the stomach were principally caused by bad digestion or stress. This was the official position endorsed by the medical community for years, and common treatment of peptic ulcers was to eat diets that were low in acid to prevent these stomach sores from getting worse. It has only been in recent times that this belief has been discarded in favor of a different one. The medical community now fully believes that bacteria and ulcers are highly connected, and in actuality, certain forms of bacteria create ulcers.
When bacteria and ulcers of the stomach, duodenum, or the esophagus are considered, the main bacteria that has been found to be responsible for creating them is H. pylori. This bacterium is common, and it doesn’t necessarily cause ulcers in all people who are exposed to it. The benefit of knowing that bacteria can be a principal cause means ulcers are much more treatable. Most ulcers will begin to heal once the H. pylori — which eats away at the mucus membrane so digestive acid creates holes in the underlying tissue — is treated with antibiotics.
There are some instances where the connection between bacteria and ulcers of the peptic type is not as well-defined. Sometimes medications create ulcerations in the stomach and there is no evidence of H. pylori. Ulcerations may be partly caused by bacteria, but also caused by medications or behaviors like smoking and heavy drinking. If a diagnosed ulcer is not responding to antibiotic treatment, doctors might look to other contributory factors and recommend behavioral modifications.
To confuse matters, different types of ulcerations that aren’t present in the digestive tract may not be principally caused by bacteria. Ulcers on the feet or legs are often the result of poor circulation, and these are particularly concerning when they occur in people with diabetes. These sores more easily become infected with bacteria because of poor circulation, and they can be difficult to treat.
Mouth ulcers can have different causes, including the use of certain medicines, especially chemotherapy medicines, or viruses. They could also be vulnerable to bacteria, just as any other open sore is, and they need to be carefully watched for signs of infection. In non-digestive tract cases, bacteria and ulcers have a reverse causal connection, where developing ulcers place people at more risk for bacterial infection.