Did you know that a healthy mouth contributes to a healthy body? With its warm and humid atmosphere, the mouth is the perfect place for a rich and diverse microbiome. Many of the bacteria that are present in our bodies enter the mouth through food and breath, which allows them to spread to the rest of the body. Everyone has their own unique oral microbiome. It varies depending on your temperature, age, acidity and saliva and it is still very unstable when you’re young.
During the first years of life, the bacterial richness and diversity in the mouth increases significantly. In general, Streptococcus and Actinomyces are the initial colonizers, later Veillonella and Fusobacterium add themselves. Around the age of six the oral microbiome stabilises. The bacterial ecosystem of children is very influenceable. For example, studies show that the microbiome observed around the age of three may be linked to the presence or absence of caries at a later age. This was not the case at the age of three months.
Not yet all the different types of bacteria in the mouth have been identified, but it is believed that there are some 750 different species. That amounts to about 10 billion bacteria!
Currently, scientists are working on the identification and characterization of the main groups that are present in a healthy mouth: Streptococcus, Actinomyces, Veillonella, Fusobacterium, Porphromonas, Prevotella, Treponema, Nisseria, Haemophilis, Eubacteria, Lactobacterium, Capnocytophaga, Eikenella, Leptotrichia, Peptostreptococcus, Staphylococcus and Propionibacterium.
Healthy mouth, healthy body
A healthy mouth is a balance between good and bad bacteria. Most bacteria are commensal or benign. However, they can become pathogenic in response to environmental factors such as diet. Personal oral hygiene also influences this process, as bacterial or viral infections can disrupt the balance.
Good bacteria suppress the harmful bacteria and prevent inflammation of the gum, bad breath and plaque. Your mouth also contains bacteriophages: viruses that kill bacteria. They create biofilms that colonise hostile areas, which allows them to battle harmful bacteria naturally.
Commensal bacteria and viruses help maintain our immune system. A healthy oral flora is important for overall health, because bacteria can spread from the mouth to other parts of the body.
Saliva plays an important role in maintaining your healthy oral microbiome. It contains anti-microbial systems and proteins capable of binding themselves to bacteria. Proteins and carbohydrates in the saliva provide a continuous food source for the bacteria.
The balance of the microbiome can for instance be disturbed by excessive intake of sugar. Bacterial species such as Streptococcus mutans convert sugar into lactic acid that causes tooth decay.
Bacteria also enter our mouth when we breathe, allowing them into our airways. Mucous membranes in the airways produce mucus that filters the inhaled air. Some bacteria like to nest in this mucus and adhere here when we breathe in air. Our immune system works together with our body’s own bacteria to put the harmful bacteria out of action.
- Avila, M., Ojcius, D. M., & Yilmaz, O. (2009). The oral microbiota: living with a permanent guest. DNA and Cell Biology,28(8), 405–11. doi:10.1089/dna.2009.0874
- Lif Holgerson, P., Öhman, C., Rönnlund, A., & Johansson, I. (2015). Maturation of Oral Microbiota in Children with or without Dental Caries. PloS One, 10(5), e0128534. doi:10.1371/journal.pone.0128534