General information about our oral microbiomes
- The mouth is an important gateway to our body. Our mouths are inhabited by around 300 different types of microbes. They make up our oral microbiome.
- The oral microbiome is second only to the lower gut in terms of the number and the different kinds of microbiota. It is made of bacteria, fungi, viruses and protozoa.
- Humans, like other animals, evolved with these microbes over the millennia, and we have come to rely on each other.
- Microbes love our mouths! The varied surfaces of the mouth, and particularly the presence of teeth, moisture (from saliva) and the food we eat make the mouth a welcoming home. They move in as soon as we are born!
- Microbes often work together. Similar to the algae and molluscs that build up on the bottom of ships, our teeth provide perfect surfaces for entire communities to be built! These communities are called biofilms, and are usually made up of a range of microbes that like living together. Some microbes only move in once we have teeth, and other microbes have made conditions just right. They form ecosystems, like found in forests and other natural environments.
- Depending on what we eat, and how we look after our mouths and our health, these ecosystems can be completely unnoticed, or lead to a furry feeling, or dental plaque. If left for too long, the biofilm can develop into dental calculas, which only your dentist can remove! Similar to ship hulls, if not regularly cleaned teeth require intensive scraping and sometimes patching (aka fillings).
- Importantly, having biofilms (and the microbes they comprise) in our mouths isn’t bad. Having a diverse array of well cared for oral microbes can not only protect our gums and teeth, but can also help protect the rest of our body!
- Just like us, microbes need food to eat and this is plentiful in the mouth. Our saliva (which is brimming with molecules from our body and our microbes), the food we eat and the waste products of other microbes all help nourish our oral microbiome. A varied diet is important for our mouths and stomachs!
- So, our diets have a big influence over which microbes we are supporting. It seems that the foods humans now eat the most of, like refined flours and added sugars, do not support healthy biofilms.
- Added sugar, and cooked refined flour (which becomes sugar like) feeds microbes that make acid. This acid disrupts biofilms and eats away at our teeth, causing tooth decay. Tooth decay is one of the most common human diseases!
- Studies of the teeth of our ancestors suggest that increasing intakes of added sugar and refined flours has led to worse oral health over the past 10,000 years
The best ways to help our microbes and reduce tooth decay is to limit the number of times we eat sugar each day, drink water, and brush! Leaving time between meals/snacks also gives time for our saliva to help return things to a good balance.