Study: Oral indicators may reveal the brain's information processing speed

The researchers, led by Joanna E. Lorie from the University of Exeter, in collaboration with researchers from the Free University of Brussels, collected blood samples, saliva, and tongue swabs, and subjected participants to tests measuring memory, attention, emotion recognition, and information processing speed, in addition to measuring blood pressure.

The results showed that the abundance of certain types of bacteria was associated with faster response times in specific cognitive tests, but the nature of these associations varied depending on the type of test and the country.

Higher levels of "Prevotella histicola" bacteria were associated with faster responses in some tests among participants in both countries, despite the difference in the nature of the tasks they underwent.

"Haemophilus parainfluenzae" bacteria were also associated with faster responses in emotion recognition and visual learning tests, as well as better accuracy in working memory among participants in Belgium.

In the United Kingdom, the same bacteria were associated with faster responses in some tasks, but they were also linked to slower responses in emotion recognition tests.

The researchers emphasized that the results do not necessarily mean that an increased abundance of a specific type of bacteria leads to a general improvement in cognitive abilities, as the observed associations varied by test and country.

Furthermore, the study observed statistical correlations and did not prove that oral bacteria cause an improvement or decline in brain performance.

The results indicate the importance of continuing research into the relationship between oral microbes and cognitive functions, with a need for larger studies to determine the consistency of these associations and understand the potential mechanisms behind them.