The stomach-dwelling bacteria Helicobacter pylori survives in the stomach—a hellish, churning vat of hydrochloric acid—by holing up inside that organ's pitlike glands and establishing squatter's rights. Once the germ has set up shop, Stanford University School of Medicine investigators have learned, even competing strains of the same species can't displace it, or even share its hideout.
* This article was originally published here