Guess what? If your bathroom has the sink and toilet in one room, and you flush with the lid open, there is fecal matter on everything within a 5 to 6 foot radius. Flushing aerosolizes your poop, depositing bacteria like Escherichia coli, or E. coli, directly onto your toothbrush —a nd brushing with an E. coli-loaded instrument could make you sick. “This bacteria is associated with gastrointestinal disease,” says Dr. Maria Geisinger, DDS, an assistant professor and periodontist at the University of Alabama at Birmingham.