Tongue and brain found to be linked much more closely - scientists

Researchers found a correlation between the composition of bacteria on the tongue and human cognitive abilities, including information processing speed and working memory. The study involved 60 healthy adults from the UK and Belgium. Participants with high levels of the bacterium Prevotella histicola performed cognitive tasks faster. However, the scientists stress that this is a statistical association, not a causal relationship.

Researchers from the UK and Belgium found a correlation between the composition of the microflora on the surface of the tongue and human cognitive abilities. The study involved 60 healthy adults: half around the age of 20, the rest 60-70 years old. The scientists analysed bacteria from the tongue and compared them with the results of tests for memory, attention, emotion recognition and speed of thinking. Participants with a higher level of the bacterium Prevotella histicola performed some cognitive tasks faster. The results for Haemophilus parainfluenzae were ambiguous. The researchers stress that this is a statistical association, not proof of a causal relationship. Age remained the most robust predictor of cognitive measures. The composition of bacteria differed between residents of the two countries, which points to the influence of external factors. The scientists did not rule out the influence of diet, sleep and physical activity. Larger studies are needed to confirm the results.