Helicobacter pylori causes stomach ulcers and is linked to gastric cancer. How does this microbe survive in the destructive environment of the stomach? Huang et al. looked at how H. pylori manages to make its way to the gastric epithelium, where it can reside relatively unscathed by the stomach’s defenses. H. pylori express a protein chemoreceptor, TlpB, that sniffs out urea released by the gut epithelium. The bugs follow a urea trail to the epithelium and simultaneously degrade the urea to generate ammonia and bicarbonate, which can help to buffer the microbe from the stomach acids. The authors watched how the bacteria locate and swim toward epithelia within seconds, attracted by minute amounts of urea….