Testing for and treating H. pylori for gastroesophageal disease is now mainstream standard of care. However, study results show two sides of H. pylori; it is both protective and harmful. Let’s look to further evidence to sort this out.
H. pylori protects against some G.I. cancers
A study reported in 1998 showed that certain H. pylori strains containing the “Cag-A protein” protect from stomach acid diseases. That’s because these strains can lower stomach acidity (i.e. raise pH) and were found to prevent Gastroesophageal Reflux Disease (GERD), Barrett's esophagus (pre-cancerous changes) and esophageal cancer. Other reports corroborated this fact, demonstrating a protective role for H. pylori in GERD (gastroesophageal reflux disease).
Moreover, in 2005 researchers reported that it was the absence, not the presence of H. pylori that increased the risk of developing esophageal cancer. Of 128,992 patients who were followed up with nearly 40 years later, 52 developed esophageal adenocarcinoma. Researchers matched control subjects according to age, gender, and race; then they compared alcohol consumption, body mass index (BMI), cigarette smoking, education level, and blood tests for H. pylori IgG antibodies and H. pylori Cag-A protein. The researchers concluded that being overweight and cigarette smoking were strong independent risk factors for esophageal adenocarcinoma—but the presence of H. pylori infection markedly decreased that cancer risk.
Interesting, huh? Here is ample evidence that the absence (not the presence) of H. pylori in the stomach leads to cancers of esophagus!
H. pylori may cause some G.I. cancers
Although H. pylori seems to prevent acid reflux-associated diseases of the stomach and esophagus, the risk of developing stomach cancer via H. pylori infection outweighs the benefits of H. pylori infection. In a 2017 report, Japanese researchers intricately described the mechanism by which H. pylori apparently directly causes stomach cancer, concluding that “Chronic infection with Helicobacter pylori cag-A positive strains is the strongest risk factor of gastric cancer.”
While this intense examination of H. pylori virulence