Scientists from Mexico and the USA report that a combination of Enterococcus faecium and agave inulin led to improvements in performance in a Morris Water Maze, which is a test of learning and memory.
The data, published in Frontiers in Aging Neuroscience, also showed that the better performance in the maze was correlated with lower levels of pro-inflammatory cytokines.
Importantly, consumption of pre- and probiotics was associated with increases in levels of brain-derived neurotrophic factor (BDNF), described by the researchers as an “important neurotrophic factor participating in memory and learning”.
“Collectively, our results suggest that prebiotics and probiotics improve learning and memory through an increase in butyrate which in turn, provoke an increase in BDNF and a decrease in pro-inflammatory cytokine concentrations in the hippocampus. The effect of pre- and probiotics is reinforced by their combination, which suggests that there is a synergistic effect that makes [synbiotics] a better therapeutic strategy for MCI [mild cognitive impairment],” they wrote.
“The [synbiotic] effect of the probiotic E. faecium and the prebiotic agave inulin seems to improve the cognitive function of middle-aged rats.”
The study included 52 male rats randomly divided into four equal groups. The rats’s diets were supplemented with 1) water (control group), 2) probiotic (E. faecium), 3) prebiotic (agave inulin), or 4) symbiotic (E. faecium + inulin) for five weeks.
The results showed that the symbiotic group performed significantly better than the other three groups for the Morris Water Maze, showing improvements in spatial memory. However, no significant differences between the groups were observed for the Pavlovian autoshaping test, which suggested that associative memory was unaffected.
In addition, pro-inflammatory cytokine and IL-1beta levels correlated with better performance in the maze test for the synbiotic-fed animals.
Synbiotic consumption was also associated with higher butyrate levels, a short chain fatty acid “with anti-inflammatory properties that also influences the production of BDNF”, said the researchers.
“The present work shows that there is a relationship between the microbiota and the brain, and presents for the first time that the consumption of probiotics and prebiotics improves synaptic plasticity, impacting memory and learning processes; this finding is of great importance and provides for a possible clinical application and possible treatment in the MCI area,” they wrote.
“The current results clearly show that with [synbiotic] supplementation, it is possible to improve the memory of individuals with cognitive impairment generated by the aging process.”
Source: Frontiers in Aging Neuroscience
10: 416, doi: 10.3389/fnagi.2018.00416
“Probiotics and Prebiotics as a Therapeutic Strategy to Improve Memory in a Model of Middle-Aged Rats”
Authors: A. Romo-Araiza et al.