Everyone has bacteria in their mouths and while some of these microorganisms can protect us from external pathogens, others can actually cause oral disease. Previously it was believed that the specific type of bacteria in our mouths was determined by our genetics. However, new research shows that the microorganisms that inhabit a person’s saliva are predominantly determined by our households, not our genetics. This research is important because it means that if environmental influences have more of an effect than genetics over our salivary microbiome, then it means we have the potential to change our behavior to improve our oral health. So, if you have gum disease, it’s time to stop blaming your genes and become a neurotic daily flosser.