Did you floss today? 🧠Your mouth talks to your brain

Why oral health could matter more than you think (and what you need to know about mouthwash)

If you’ve been slacking on flossing or relying on mouthwash to do the work for you, consider this a little nudge.

Brushing your teeth keeps your mouth clean - but clean from what?

It helps control certain bacteria, the ones that cause tooth decay and gum disease. But your mouth is home to far more than just these troublemakers.

It’s a whole ecosystem of bacteria, viruses, and fungi, known as your oral microbiome​.

And keeping your teeth and gums healthy may not only be about fresh breath.

New emerging research links oral bacteria to brain health, including Alzheimer’s, Parkinson’s, depression, and anxiety.

One study even suggests childhood trauma may affect the oral microbiome long-term, and that there’s a link between certain oral bacteria and how helpful someone finds talking therapy.

What we’ll cover today:

• What is the oral-brain connection?

• How is your mouth’s microbiome linked to mental well-being?

• Should you really use mouthwash?

• Simple tips to support your oral microbiome

What is the oral-brain connection?

Your mouth is home to around 700 types of bacteria​.

Some are helpful, keeping harmful ones in check. Others, like those linked to gum disease, can cause problems.

But these bacteria don’t just stay in your mouth. If your gums are inflamed, early science suggests they may enter your bloodstream and potentially even travel to your brain​.

One meta-analysis found that people with severe gum disease were nearly three times more likely to have Alzheimer’s​.

Could our oral health be affecting our brain health in ways we never realised?

Can the bacteria in your mouth affect your mood?

People with anxiety and depression tend to have different oral bacteria than those without these conditions​​.

One study found that individuals with childhood trauma, even decades later, had higher levels of inflammation-linked oral bacteria, suggesting that early life stress may shape immune function even later in life.

The researchers also found that certain types of oral bacteria were linked to how much talking therapy helped with their mental well-being.

People who responded well to therapy had different bacteria in their mouths, which the researchers suggested was possibly because these bacteria may help manage stress and immunity, making recovery easier.

Could it work both ways?

Of course, mental health and brain conditions can change the oral microbiome.

Stress raises cortisol, which affects saliva and bacteria, certain neurodegenerative diseases impact motor control, making brushing harder, and some medications for depression and brain health can dry out the mouth, making it easier for harmful bacteria to thrive​​.

But emerging research hint it may also work the other way around:

• Changes in the oral bacteria of people with Alzheimer’s can appear early on, suggesting these bacterial shifts could be linked to the disease, not just because of potentially poor brushing or care.

• Similarly, people with depression and anxiety have different oral microbiomes, even when brushing habits are the same​​.

How could bacteria in your mouth influence your brain?

This is early evidence showing how bacteria in the mouth might affect brain health. Most research has been done in animals, but some studies are starting to look at humans.

Here's what we think so far:

• Inflammation: Gum disease triggers inflammation, which can spread to the brain and is linked to conditions like Alzheimer’s and depression.

• Bacteria in the bloodstream: Oral bacteria can enter the bloodstream through inflamed gums, potentially reaching the brain and causing inflammation.

• Nerve pathways: Some bacteria may interact with the brain via the vagus nerve, which connects the mouth, gut, and brain.

Should you really use mouth wash?

Mouthwash can be helpful, but picking the right one matters.

Alcohol-based mouthwashes can kill both harmful and helpful bacteria in your mouth, potentially upsetting the balance of your oral microbiome.

Chlorhexidine can help with gum disease, but it can lower ‘good’ bacteria and overall diversity in your mouth if you use it longer than your dentist recommends.

Here’s what to do:

• Use an alcohol-free fluoride-based mouthwash: It protects enamel and doesn’t harm good bacteria.

• Only use chlorhexidine short-term: Long-term use may disrupt your oral microbiome.

• Try probiotic mouthwash: Early research suggests it might help balance the bacteria in your mouth.

9 ways to look after your oral microbiome

Taking care of your oral health goes beyond just brushing your teeth.

While I'm not a dentist, here are 9 simple tips that can help keep your mouth healthy and support overall well-being.