How harmful are the bacteria in our mouths?

Our mouths contain around 20 billion microbes! But can they make us ill and will good oral hygiene help us keep on top of them?


It’s almost cold and flu season, and we’ll be hearing the usual good advice to wash our hands thoroughly to prevent passing on viruses. But if the average human mouth is already home to between 34 and 72 different strains of bacteria – around 20 billion microbes at any one time – should we be more concerned about good hygiene?

Bacteria and the immune system

We used to assume that the way to beat allergies was by cleaning homes and surfaces regularly to restrict contact with allergens and germs. But this led to a decrease in the kinds of bacteria we need to keep our immune system strong.

Besides this, an increase in antibiotic use, pasteurised foods, and births by caesarean section – among other lifestyle changes – all began to limit our exposure to different strains of bacteria, causing allergy diagnosis to increase.

But over the years, research into bacteria has changed the way we understand illness.

You’ve probably seen adverts for probiotic yoghurts that claim to promote healthy gut diversity. This is an example of how some scientific researchers think we need to allow bacteria back into our bodies to build up a healthy immunity – in fact, some even suggest we should eat dirt! We certainly wouldn’t go that far!

Harmful bacteria in your mouth

The reality is, bacteria exists in our mouths naturally, so there’s nothing to worry about there. Unless you ignore your dental hygiene, that is.

The most common bacteria – Streptococcus mutans – feeds on the starches and sugars from food particles. So if you don’t eat a balanced diet and clean your teeth regularly – even throughout the day by rinsing with mouthwash, chewing sugar-free gum or drinking water – plaque can build up, eventually leading to tooth decay and gum disease.

The second harmful bacteria, Porphyromonas gingivalis, isn’t usually found in healthy mouths. It is a progressive disease that is usually linked to periodontal disease – the advanced form of gum disease – and affects the tissue and bone. It can cause dental pain and eventually tooth loss, which regular dental and hygienist check-ups can help prevent.

To clean or not to clean?

Unlike excessively cleaning your home environment, cleaning your teeth, gums and mouth won’t decrease your immunity since we swallow 100 billion microbes every day!

When it comes to the bacteria in our mouths, the harm doesn’t come from the bacteria itself but from its direct and prolonged contact with residual food particles. So long as you take the proper precautions and practice good dental care, there’s no need to be concerned.

In fact, there’s also no need to be so stringent with hand washing since bacteria can help your gut and immune system when winter rolls around. In your general day-to-day business, such as using public transport or going for a walk, you might just be doing your mouth and your body a favour by putting the antibacterial gel to one side.

Of course, there are some instances when it’s always important to wash surfaces and hands: after handling raw meat to prevent food poisoning; after using the toilet; and when you’re around high-risk individuals such as young children, the elderly or those undergoing medical treatment.

If you’re looking for dental treatment in Notting Hill and would like to book a check-up with one of our Number 18 Dental hygienists or dentists, contact us today to make your appointment.

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