Last week, some restaurants began pulling tomatoes from their menu because of an outbreak of salmonella. How do tomatoes get salmonella, you ask? Good question. The one-word answer, as reported by Slate: poop. Salmonella is a bacterium that lives inside the intestines of animals.
Says Slate, "Livestock animals, especially when kept in large numbers in confined spaces, can contract salmonella and carry the bug without showing any symptoms at all. Infected cows, pigs, and chickens shed the bacteria in their waste, which is sometimes used to fertilize nearby fields." Essentially, large-scale factory farming is what's making your tomato make you sick.