Oral Health
GABRIELLA NAGY
3 MIN READ

New Study Links Oral Bacteria to Brain Health — Including Alzheimer’s Risk

New Study Links Oral Bacteria to Brain Health — Including Alzheimer’s Risk

A new study led by the University of Exeter is shining fresh light on a fascinating question: Could the bacteria in your mouth play a role in your brain health, even influencing your risk of Alzheimer’s disease?

The findings are part of a growing body of research connecting oral health with cognitive function, suggesting that brushing your teeth might do more than just protect your smile, it could support your memory too.

The Oral Microbiome: More Than Just Dental Health

Your mouth is home to over 700 species of bacteria, collectively known as the oral microbiome. While many of these microbes are helpful or harmless, poor oral hygiene can cause an imbalance, leading to gum disease and other issues. But now, scientists believe this imbalance might also have consequences far beyond your mouth - potentially affecting your brain!1

What the University of Exeter Study Found

In the recent University of Exeter study, researchers analysed mouth rinse samples from individuals with varying levels of cognitive function. The goal? To see whether specific bacteria might be linked to memory and brain performance.

Here’s What They Found:

  • Helpful Bacteria: Higher levels of Neisseria and Haemophilus species were associated with better memory and attention, and greater levels of nitrite, a molecule linked to brain communication and memory.
  • Concerning Bacteria: On the flip side, elevated levels of Porphyromonas were more commonly found in those with memory problems. Prevotella species, which were linked to lower nitrite levels, were also more common in people carrying the APOE4 gene, a known risk factor for Alzheimer’s.2

These findings suggest that the balance of bacteria in your mouth could be linked to cognitive performance and even provide a potential early warning system for future brain health risks.

How Could Oral Bacteria Affect the Brain?

Researchers propose two main pathways through which oral bacteria might influence brain health:

  1. Bacteria Entering the Bloodstream: Harmful bacteria may enter the bloodstream via inflamed or infected gums, potentially reaching the brain and contributing to inflammation or damage.
  2. Nitric Oxide Disruption: Beneficial oral bacteria help convert dietary nitrate (found in vegetables) into nitric oxide, which is crucial for brain function. An imbalance in the microbiome may reduce nitric oxide production, impairing brain communication and memory.3

How You Can Support Both Oral and Brain Health?

While more studies are needed to fully understand the mouth-brain link, there are steps you can take right now to support a healthy oral microbiome, and potentially your cognitive function:

  • Brush and floss regularly to remove harmful bacteria and prevent gum disease.
  • Eat a vegetable-rich diet to support nitrate intake and nitric oxide production.
  • Visit your dentist regularly to catch early signs of gum issues.
  • Consider oral probiotics, which may help balance your oral microbiome.
  • Use natural mineral toothpaste and oral care products that support the balance of your oral microbiome without harsh chemicals. Options that include ingredients like hydroxyapatite can help remineralise enamel and support long-term oral health.4,5

The Takeaway

Your oral health is about much more than teeth and gums. It may offer a window into your brain’s future. The latest research from the University of Exeter adds weight to the growing evidence that the oral microbiome could influence memory, attention, and even the risk of Alzheimer's disease.

So next time you brush your teeth, remember, you might also be brushing up on your brain health.

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Gutology Hydroxyapatite Toothpaste (120ml)
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References

  1. Chien et al. Effects of oral health intervention strategies on cognition and microbiota alterations in patients with mild Alzheimer’s disease: A randomised controlled trial. Geriatric Nursing. 48, 103-110.
  2. L’Heureux et al. Oral microbiome and nitric oxide biomarkers in older people with mild cognitive impairment and APOE4 genotype. PNAS Nexus. 4(1):543.
  3. Cross, P.I. 2025. Some bacteria in the mouth may play a role in memory loss and dementia. **Available at: https://www.medicalnewstoday.com/articles/some-bacteria-mouth-microbiome-may-play-role-memory-loss-dementia
  4. HSI, 2025. How Oral Bacteria May Influence Dementia Risk (New Research). Health Sciences Institute. Available at: https://hsionline.com/2025/02/04/how-oral-bacteria-may-influence-dementia-risk-new-research/
  5. Askarova et al. The Links Between the Gut Microbiome, Aging, Modern Lifestyle and Alzheimer's Disease. Front Cell Infect Microbiol. 18;10:104.