Bacteria are swimming in our guts. That’s not necessarily a bad thing. Probiotics, for example, help us digest food, make vitamins, and destroy rogue, possibly cancer-causing mutated cells before they spin out of control. But bad actors can also sneak in and wreak havoc. That’s especially true with Helicobacter pylori (H. pylori), a bacterium that has infected about half the world’s population.
The clearest connection between H. pylori and bad health outcomes is with gastric cancer. H. pylori is typically passed from person to person as they share food and drinks, and it goes “right to the stomach and attaches itself to stomach cells,” said Wael El-Rifai, M.D., Ph.D., associate director of Basic Science and co-leader of the Tumor Biology Program at Sylvester Comprehensive Cancer Center. After binding to those cells, it injects CagA, an oncogenic bacterial protein, into them and reprograms cells.