“You are what you eat.” It’s also said that our memories make us who we are, and together these assumptions may be more relevant than ever. New research on the gut-brain axis says that ‘what’ we eat (and how it’s metabolized) may have a lot to do with ‘who’ we are, in memory at least.
This newer field of research seeks to understand the relationship, and significance between what we eat, how it’s processed by the gut, and the health of our brains. This isn’t entirely a matter of healthy eating either, it’s what happens during digestion that gets complicated here.
In fact, gut-microbes may stand as ‘gatekeepers’ between what actually makes it across to the brain (and in what form). This axis may ultimately prove determinant in the functions of healthy memory, learning, and cognition.
Probiotics and Memory: Evidence of the Gut-brain Axis?
It’s important to have a healthy balance of probiotic microbes, but usually that’s said for the sake of digestion. Now we know probiotics may be essential to help get the brain all that it needs.
For healthy people, but especially in the case of those with genetic risk factors (e.g. Alzheimer’s), it’s reported that memory may be regulated through probiotic activities. Particularly of interest are lactobacilli strains of bacteria .
Per their name, this family of bacteria largely produce the chemical known as lactate. Our bodies also produce lactate during metabolism and exercise, and as it turns out it may have an essential role in learning and long-term memory .
Probiotics and Cognition
One recent study evaluated memory improvements in mice with genetically poor memory. Increased lactate in the brain was found to reduce memory impairment. More importantly, this finding was produced directly by probiotic supplementation of lactobacilli, an example of groundbreaking evidence that what happens in the gut may cross the blood-brain-barrier (BBB) .
One benefit of lactate is that it may fuel neuronal growth. Since brain cells may use it as an alternative energy source it can support memory and learning. Also, like exercise where lactate from muscles enters the brain and releases ‘Brain Derived Neurotrophic Factor’ (BDNF), evidently probiotic-lactate may do the same .
Neuroprotective Compounds and Gut-health
It’s known that BDNF may be a potent neuroprotectant. So besides a core energy source for neurons – fueling memory and learning – we see how increased lactate from probiotics may help shield against cognitive decline. Similarly, lactate from probiotic supplementation may also increase levels of GABA in the brain .
GABA is an amino-acid with great value to memory and learning, as well as regulatory purposes in the brain. Also found in matcha green tea, it may protect against overexcitement and cognitive symptoms like anxiety .
The Future of Gut-brain Axis Research
Researchers aren’t sure yet whether probiotics are producing more GABA, or if lactate is encouraging the body to release more of its own . Nevertheless it’s exciting how these neurochemicals elevate working memory , and especially how probiotics are now associated in increasing those levels.
Recent genetic modelling supports probiotic supplementation as one means to positively influence developmental and cognitive disorders . And researchers overall are set on future studies to better understand the extensive considerations of the gut-brain axis, especially this research may translate to human results.
The Bottom Line
Correlations between higher levels of several metabolites, including lactate, GABA and BDNF demonstrate the importance of gut-brain axis research. It’s likely that probiotic supplementation will remain a possible candidate to promote healthy memory and learning, including against cognitive disease.
Taken together, this research provides new evidence for a link between gut health and memory, possibly yielding a path to future treatment options against cognitive diseases, as well as new understandings between the food you eat, your microbiome, and your cognitive health.
Ultimately, it’s intriguing how health may require balance in the gut to best feed your brain. Certain antibiotic treatments or lifestyle factors may contribute towards imbalance (dysbiosis) , where people affected may be losing on critical neurochemicals.
While there’s no proven method for gut health, there is good reason to take promise in naturally fermented foods, a whole-food diet, and wise choices made alongside your physician in the case of supplementation or other concerns.
If you’re worried about your gut-brain axis, try to relax. Check your local health food store for naturally fermented foods, and be sure to stay tuned for future research.
And if you’re already a daily matcha green tea drinker, it’s noteworthy that antioxidant catechins found in green tea may offer probiotic benefits .
-Team Matcha Kari
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 Mao, J. H., Kim, Y. M., Zhou, Y. X., Hu, D., Zhong, C., Chang, H., ... & Celniker, S. E. (2020). Genetic and metabolic links between the murine microbiome and memory. Microbiome, 8, 1-14.
 Francino, M. P. (2016). Antibiotics and the human gut microbiome: dysbioses and accumulation of resistances. Frontiers in microbiology, 6, 1543.
 Ma, Y., Ding, S., Fei, Y., Liu, G., Jang, H., & Fang, J. (2019). Antimicrobial activity of anthocyanins and catechins against foodborne pathogens Escherichia coli and Salmonella. Food Control, 106, 106712.