Helicobacter pylori (H. pylori) is a bacteria that lives in the stomach; it’s been around for over 50,000 years. It’s likely a cause of most Duodenal Ulcers (we all talk about “stomach ulcers,” but most of them occur in the duodenum, the very first part of the small intestine next to the stomach; see Diagram — Gastrointestinal System). It’s also a cause of Gastritis, and involved in Stomach Cancer.
Actually, H. pylori doesn’t do anything to the stomach. Rather, it stimulates our immune system, which is what winds up causing the damage. Patients are often told they “have a bacteria in their stomach,” which makes them think of the type of Gastroenteritis with repeated vomiting for a day, due to toxins from bacteria in contaminated food. This is completely different.
Lots of people have H. pylori, and nothing ever happens. In the U.S., it may be present in 10% of people by age 30, and half of people over 60. In poor countries, it’s even more prevalent. There’s no reason at all to go testing everyone for the germ. We mainly just do tests on patients who we think have an Ulcer or Gastritis [but see below at the bottom].
There are four types of tests:
- Biopsy: Done by the Gastroenterologist during endoscopy
- Breath Tests: Done at many labs
- Stool Test: Take specimen collector home & send it in
- Blood Test: The most common, and least accurate (and least useful; see below)
Someone with an ulcer or gastritis usually has it diagnosed by endoscopy. However, many patients with suggestive symptoms often just get treated with antacid medication, which can cure both conditions. Those patients should get tested; for these conditions, the blood test is easiest if they’d never been treated before. But “suggestive symptoms” includes pain virtually every day, often much of the day. After all, these diseases involve an actual sore or abrasion, which hurts due to constant contact with stomach acid and digestive enzymes. They’re different from Dyspepsia, i.e. indigestion on & off or whenever.
Treatment for H. pylori involves taking 3 or 4 medicines together for up to 2 weeks. The medications include proton pump inhibitors (the strongest type of antacid), plus at least two different antibiotics. One of the most common antibiotics used can cause fatal muscle breakdown if mixed with statin drugs for cholesterol, so if you’re on one of those, stop it during the treatment.
It’s also recommended to test for H. pylori in people under age 50 with simple dyspepsia (indigestion) that isn’t helped by diet changes & a variety of medications. The bacteria does not cause dyspepsia. However, studies show that if the patient tests positive and receives treatment, they may improve enough so as not to need referral for endoscopy (patients over 50, when there’s more risk of stomach cancer, always get referred). Maybe it’s a placebo effect, nobody knows, but money gets saved and patients feel better. In such cases, the test should be a breath or stool test.
And what about the blood test? It identifies an antibody, which does not prove active infection. Also, 20% of results may be false-positive. The antibody test is only useful if it’s negative, ruling out H. pylori. Unfortunately, many clinicians reflexively test for it when patients complain of whatever stomach problems, and blood tests are easy to obtain. I’ve even seen this done for patients with Gastroesophageal Reflux (GERD; heartburn), which is definitely not caused by the bacteria. Then, if the blood test is positive, patients are given treatment, which can cause various side effects, making them feel lousy 2 weeks, for no reason at all.