A recent study has revealed a connection between specific bacteria in your mouth and changes in brain functioning as you age, indicating that some bacteria may enhance memory and focus, while others could increase the likelihood of Alzheimer’s disease.
Research indicates that the bacteria residing in your mouth and on your tongue might influence brain function as you get older.
Conducted by the University of Exeter, the research identified that certain types of bacteria correlate with improved memory and attention, whereas others are associated with a higher risk of Alzheimer’s disease.
The researchers proposed two mechanisms by which these bacteria could affect brain health. One possibility is that harmful bacteria can enter the bloodstream directly, potentially inflicting damage on the brain. The other potential mechanism involves an imbalance of healthy versus harmful bacteria, which might limit the body’s ability to convert nitrate—often found in vegetable-rich diets—into nitric oxide. Nitric oxide is vital for effective brain communication and the formation of memories.
People with higher quantities of the bacteria groups Neisseria and Haemophilus demonstrated superior memory, attention, and proficiency in complex tasks, which also corresponded with elevated nitrite levels in their mouths.
Conversely, increased levels of the Porphyromonas bacteria were often found in individuals experiencing memory issues. In contrast, the bacterial group Prevotella was linked with low nitrite levels, which the researchers suggest could indicate poorer brain health and was more prevalent among individuals carrying the Alzheimer’s risk gene, APOE4.
This study, funded in part by Wellcome and the National Institute for Health and Care Research (NIHR) Exeter Biomedical Research Centre, opens up intriguing possibilities for the early detection and intervention of cognitive decline.
Dr. Joanna L’Heureux, the lead author from the University of Exeter Medical School, remarked, “Our findings imply that certain bacteria could negatively impact brain health as we age. It provokes the interesting suggestion of integrating routine bacterial level assessments into dental check-ups to identify early signs of diminishing brain health.”
While memory decline and cognitive impairment are usual with aging, when these diminutions exceed what is anticipated for normal aging, it is referred to as Mild Cognitive Impairment (MCI). Around 15% of seniors fall into this category, which is the strongest predictor for developing dementia or Alzheimer’s disease.
Published in PNAS Nexus, this study analyzed data from 110 participants over the age of 50, gathered from an online study called PROTECT that monitors the brain health of over 25,000 middle-aged individuals in the UK. Participants were divided into two groups: those without cognitive decline and those displaying Mild Cognitive Impairment, who submitted mouth rinse samples for analysis of their bacterial populations.
Co-author Professor Anne Corbett from the University of Exeter Medical School stated, “The implications of our research are significant. If specific bacteria aid in maintaining brain health while others lead to decline, adjusting the balance of oral bacteria could help prevent dementia. This could be achievable via dietary adjustments, probiotics, improved oral hygiene, or targeted treatments.”
The research paper is titled ‘Oral microbiome and nitric oxide biomarkers in older people with mild cognitive impairment and APOE4 genotype’ and is found in PNAS Nexus.
