There’s been a lot of attention focused on our guts lately. No, not your dad bod, but rather your actual guts: your stomach, small intestine, and large intestine. Mountains of research have proven that your gut is actually its own little world — it is, after all, famously referred to as the “second brain” that’s teeming with life, both beneficial and not. And that microbiome can have a significant impact on your cognitive health.
Recently, new evidence for the gut-brain axis has emerged. Researchers at Nutrition 2023, the annual meeting of the American College of Nutritionists, presented a study linking gut health to age-related cognitive health, and found that one little change can help boost your mental acuity in your golden years: taking a probiotic supplement. (The research has not yet been peer-reviewed.) Probiotics are live microorganisms “intended to have health benefits when consumed or applied to the body,” per the National Institutes of Health. While they can be sold as supplements, they’re also found in whole foods like yogurt, sauerkraut, kombucha, and kimchi.
The research team examined 169 participants between the ages of 52 and 75. They were divided into two groups based on cognitive fitness — no cognitive impairment and mild cognitive impairment. Members of each group were then given either Lactobacillus rhamnosus GG (LGG), a very common probiotic supplement that has shown promise in previous brain health studies, or a placebo for three months.
Before administering the probiotics, the research team analyzed each participant’s gut microbiome using genome sequencing to determine the bacterial makeup of each person’s gut flora. They found that in those with mild cognitive impairment, anaerobic bacteria in the genus Prevotella were more prevalent compared to those with no signs of cognitive impairment.
At the conclusion of the study, participants who began with mild cognitive impairment and received the LGG probiotic supplement showed a decrease in the number of Prevotella in their guts and, importantly, improved cognitive abilities.
“The implication of this finding is quite exciting, as it means that modifying the gut microbiome through probiotics could potentially be a strategy to improve cognitive performance, particularly in individuals with mild cognitive impairment,” study co-author Mashael Aljumaah, a microbiology doctoral candidate at the University of North Carolina at Chapel Hill and North Carolina State University, said in a statement.
“This adds a new layer to our understanding of the microbiome brain-gut connection and opens up new avenues for combating cognitive decline associated with aging.”
The findings are compelling and echo previous research into the connection between the gut microbiome and brain health. The research team is delving further and researching how specific molecules created by gut bacteria affect hormones that protect the brain and nervous system.
“By identifying specific shifts in the gut microbiome associated with mild cognitive impairment, we're exploring a new frontier in preventive strategies in cognitive health,” Aljumaah said. “If these findings are replicated in future studies, it suggests the feasibility of using gut microbiome-targeted strategies as a novel approach to support cognitive health.”