The bacteria in your mouth and on your tongue can be linked to changes in the brain function as you get older, new research suggested.
The study, led by the University of Exeter, showed that certain bacteria were associated with better memory and attention, while others were linked to an increased risk of Alzheimer’s disease.
The researchers identified two possible ways in which these bacteria can influence the health of the brain. This includes harmful bacteria that immediately enter the bloodstream, causing damage to the brain. As an alternative, an imbalance between favorable and harmful bacteria can reduce the conversion of nitrate (abundant into vegetable rich diets) into nitrogen oxide -a chemically crucial for brain communication and memory formation.
People with a large number of bacterial groups Neisseria and Haemophilus had a better memory, attention and ability to perform complex tasks. These people also had higher nitrite levels in their mouths.
On the other hand, larger levels of the bacteria, Porphyromonas, were more common in people with memory problems. While the Prevotella bacterial group was linked to low nitrite, the researchers predict that they could in turn mean a poorer brain health and occur more often in people who wear Alzheimer’s disease -Apoe4.
The study was supported by Wellcare and partly funded by the National Institute for Health and Care Research (NIHR) Exeter Biomedical Research Center. is an interesting opportunity for early identification and intervention.
Our findings suggest that some bacteria can be harmful to the health of the brain as people get older. It evokes an interesting idea for performing routine tests as part of dental controls to measure bacterial levels and to detect very early signs of decreasing brain health. ”
Dr. Joanna l’Heureux, Chief author from the University of Exeter Medical School
Although the decline of memory and brain functions is typical of old age, deterioration of mental possibilities that are greater than would be expected with normal aging is known as mild cognitive impairment. About 15% of the older adults fall into the mild cognitive impairment category, considered the largest risk factor for the development of dementia or Alzheimer’s disease.
Published in PNAS NEXUSThe study recruited 110 participants, older than 50 years from an online study called Protect who follows the brain health of more than 25,000 middle -aged people in the UK. Researchers split participants into two groups: people without a decrease in brain function and they show mild cognitive disorders. The participants in these two groups sent mouthwash samples who were then analyzed and studied the bacteria population.
Co-author Professor Anne Corbett of the University of Exeter Medical School, said: “The implication of our research is in-depth. If certain bacteria support brain function, while others contribute to the decline, then treatments that are the balance of bacteria in the mouth can be possible Changing, being part of a solution to prevent dementia.
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Journal Reference:
L’Heureux, you, et Alt Alto. (2025). Oral microbiome and nitrogen oxide biomarkers in the elderly with mild cognitive disorders and Apoe4 genotype. PNAS NEXUS. doi.org/10.1093/pnasnexus/pgae543.