If you leave your toothbrush on your bathroom counter then you could have bacteria collecting on it. Microscopy Research and Technique found that “if you leave your toothbrush sitting out, it could collect fecal bacteria. Aerosolized droplets splatter when you flush.” They can go pretty far — up to 20 feet. Yum!
To stay clean: Regularly run your toothbrush through a clean dishwasher, using standard dish detergent. A 2011 study in the American Journal of Dentistry found that this method eradicated nearly all disease-causing bacteria. Another option is to soak your toothbrush in a mouthwash that contains cetylpyridnium chloride, such as Crest Pro-Health Complete Rinse, for 20 minutes. Doing this can also beat bacteria, the study found. To avoid flying feces, store your toothbrush in a closed cabinet. Also, remember to replace your toothbrush or brush head every 3 months.