The mouth is home to more than 1,000 different species of microbes. These microbes live in the nose, mouth and throat and help to protect us against invasive disease-causing organisms. We don’t have a choice about their residency in our bodies. If we wanted to remove them once and for all we would need a blow torch. That is to say, they can’t be removed. Because of their contribution to disease, we must monitor and control their populations as best we can. To put it another way: we need them, and they need us. We must be sure that they are not having a party in our mouth. The best way to avoid having an unhealthy population of organisms is to practice good oral hygiene: brush upon wakening, after meals and at bedtime, use dental floss, and visit a dentist two or three times a year for check-ups and cleaning.We need to take care of our oral health because it is good for our brain and heart. Of course, it’s also good for our teeth, but consideration of the role of oral health in brain and heart disease will help us to understand its importance to our health and fitness.