Changes in the bacteria in a person’s mouth might signal the onset of pancreatic cancer, preliminary research reveals. The small study suggests that it eventually might be possible to screen for the deadly disease simply by analyzing a patient’s saliva, as the presence or absence of certain oral bacteria seems to indicate a higher risk. The observation, however, raises the question: Does pancreatic cancer prompt changes in an individual’s oral bacterial landscape, or are such shifts actually driving the onset of disease?