For years, scientists have known that the biological composition of a person’s mouth is only partly determined by his or her genetics. In other words, your hereditary line has a lot to do with how healthy your teeth and gums remain throughout the course of your life. We know that prevention, oral health habits and good lifestyle choices, can put you in the driver’s seat on the road toward or away from tooth decay and periodontal disease (gum disease). But recently, researchers have discovered that the salivary microbiome, the petri dish that is a human’s mouth, is also determined by a person’s home as well. This means that your home and the people you live with, your family or roommates, can have a surprising impact on the kinds of bacteria that live in your saliva.
The Good & Bad of Bacteria
There are over 800 different species of micro-organisms that live in the mouth of every individual. These bacteria can be beneficial or detrimental. Some microbes, mostly bacteria, originate in the body while others make their way into the mouth from the environment. After all, we’re taught very young to wash our hands and cover our sneezes to best defend others and ourselves from colds and other infections. So how is this information new?
Household Members Share the Same Salivary Makeup
Not only can household members share bacteria—a person can send their spit flying up to 25-ft with the force of a sneeze or an enthusiastic conversation—they can also adopt a household member’s salivary microbiome. In other words, your microbiome isn’t isolated. Instead, it absorbs microbes from the environment and changes its composition based on others. This is a huge revelation. It means that fighting the bacteria that causes plaque may be more effective if it’s not only practiced on an individual level.
“If you could promote a microbiome associated with health as opposed to disease by behavior, for example, then this could affect all household members,” says Adam Roberts, a senior lecturer in antimicrobial chemotherapy and resistance at the Liverpool School of Tropical Medicine.
The Household is Stronger than the Individual
Salivary makeup is transferred by a variety of ways, even if a household consists of vigilant hand-washers. Saliva is shared on computer keyboards, cup rims, TV remotes and doorknobs. The presence of saliva increases in households with children younger than ten years old. As a parent, it’s important to practice good oral health, not just preach it. This is because a parent’s salivary microbiome can be transferred to a child, altering that child’s otherwise healthy and balanced salivary composition.
There is still much research to be done about the link between saliva and health. For now, we know that a household’s oral health can be a stronger defense against tooth decay than any one individual.