Could the microbial inhabitants of your oral cavity serve as indicators of your susceptibility to dementia?

Recent studies are revealing intriguing connections between the oral microbiome—an intricate community of bacteria residing in our mouths—and cognitive health. The nature and composition of these microbial populations may significantly influence brain function as we advance in age, potentially contributing to normative aging or the onset of dementia.

Scientific investigations are uncovering unexpected correlations between the bacterial flora in our mouths and neurological well-being. A recent study conducted by my colleagues and me indicates that certain bacterial species may bolster memory and cognitive abilities, while others could signal early cognitive decline.

This prompts the fascinating hypothesis that dietary choices and interventions aimed at modulating our oral microbiome could ultimately play a role in preserving cognitive function as we age.

Our research involved analyzing saliva samples from 115 adults aged over 50, wherein 52% exhibited healthy cognitive function, while the remaining 48% displayed preliminary signs of memory and cognitive decline.

Our analysis revealed that individuals with elevated levels of specific bacterial groups, namely Neisseria and Haemophilus, performed significantly better on cognitive assessments. Notably, these individuals exhibited enhanced memory skills and greater capacities for attention and complex task execution.

Additionally, these participants displayed increased levels of nitrite ions in their oral cavities, a compound generated by bacteria during the decomposition of dietary nitrates—naturally abundant in a vegetable-rich diet.

The breakdown of nitrite into nitric oxide, a molecule known to improve vascular circulation, including cerebral blood flow, underscores the potential cognitive benefits of consuming nitrate-rich vegetables, such as leafy greens and beetroot. This could prove particularly relevant as we age.

Our ongoing research is exploring the possibility of utilizing nitrate-rich beetroot juice to enhance cognitive function among older adults by capitalizing on oral bacteria.

Conversely, certain bacterial populations may pose risks rather than benefits; our study identified specific groups potentially linked to diminished cognitive health.

Specifically, the Porphyromonas group, often associated with periodontal disease, was found to be more prevalent in individuals exhibiting memory impairments compared to their healthier counterparts. Additionally, the bacteria Prevotella were correlated with lower nitrite levels and were more frequent in individuals possessing the APOE4 gene, a risk factor for Alzheimer’s disease.

These findings accentuate the notion that some bacteria may adversely affect cognitive health throughout aging. They also raise the prospect of integrating regular evaluations of oral bacterial flora into standard dental check-ups to facilitate the early detection of cognitive decline.

Significant Implications

The implications of this research are noteworthy. Should specific bacteria serve to support cognitive health while others contribute to deterioration, interventions aimed at altering the bacterial balance in the mouth could emerge as innovative strategies for dementia prevention.

Encouraging the proliferation of beneficial, nitrite-producing bacteria like Neisseria, while diminishing Prevotella and Porphyromonas, may help sustain cognitive function over time. Such adjustments could be achieved through dietary modifications, probiotics, enhanced oral hygiene practices, or targeted treatments that reshape the microbiome.

While we remain in the nascent stages of comprehending the complex interrelationships between oral bacteria and cognitive health, our findings warrant further exploration.

Future research may validate the hypothesis that the oral microbiome plays a critical role in sustaining cognitive function. By paying closer attention to our oral bacterial populations, we may uncover novel pathways for the detection and potential delay of dementia.

In the interim, maintaining good oral hygiene, regular dental check-ups, and a diet rich in nitrates—such as leafy green vegetables—remains advisable to support the beneficial bacteria in our mouths.

Joanna L’Heureux, Postdoctoral Researcher, Public Health and Sport Sciences, University of Exeter.

This article is republished from The Conversation under a Creative Commons license. Read the original article.