The fecal content of Veillonellaceae family bacteria correlates with cognitive parameters in young healthy human subjects

Introduction: Several lines of evidence suggest that the composition of gut microbiota influences the central nervous system function. Previous studies demonstrated that gut microbiota composition can affect the mood, anxiety and cognitive performance. However, most of the research was focused on the animal models and older humans. Relatively limited number of reports examined the influence of gut microbiota on cognitive functions in young, healthy human subjects. Material and methods: We examined the influence of gut microbiota composition on cognitive performance in 30 volunteers (24 females and 6 males; mean age 22.53 ± 1.97 yr.). In order to evaluate the cognitive performance in our subject we used three standard tests: Face/Name Association Test, Trial Making Test and Stroop Test. The composition of intestinal microbiota was determined in fecal samples using 16S rDNA V3-V4 regions analysis. Results: The study demonstrated that the proportion of Veillonellaceae bacteria (phylum Firmicutes) in the subject’s fecal matter positive correlated with the results of one of the cognitive tests — Trial Making Test. Conclusions: Our results indicate that bacteria from Veillonellaceae family may influence the level of some cognitive functions (namely executive ones). Our results are consistent with previous studies describing the potential impact of intestinal bacterial on cognitive performance.