Common probiotics can slow cognitive decline, study finds

A recent study has unveiled promising findings that may revolutionize our approach to combating cognitive decline associated with aging.

[Jan. 3, 2024: JJ Shavit, The Brighter Side of News]

A recent study has unveiled promising findings that may revolutionize our approach to combating cognitive decline associated with aging. (CREDIT: Creative Commons)

A recent study has unveiled promising findings that may revolutionize our approach to combating cognitive decline associated with aging. Researchers have discovered that the administration of a probiotic, Lactobacillus rhamnosus GG (LGG), for a three-month period led to improvements in cognitive scores among individuals experiencing mild cognitive impairment.

Notably, these cognitive enhancements were correlated with alterations in the participants' gut microbiome composition. This breakthrough opens doors to innovative, non-invasive methods that harness the power of the gut microbiome to mitigate age-related cognitive deterioration.

The Gut-Mind Connection

The notion that our gut health is intricately linked to our cognitive functions has been gaining momentum in recent years. However, the latest study, presented at NUTRITION 2023 by microbiology doctoral candidate Mashael Aljumaah from the University of North Carolina at Chapel Hill and North Carolina State University, takes this concept a step further.

Graphical abstract. (CREDIT: Clinical Nutrition)

Aljumaah, who is also affiliated with King Saud University in Saudi Arabia, explains, "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 research involved 169 participants aged between 52 and 75 years, who were categorized into two groups based on their neurological status: those with no cognitive impairment and those with mild cognitive impairment.

Within each group, participants were randomly assigned to either receive the LGG probiotic or a placebo in a double-blind, randomized clinical trial spanning three months. The choice of LGG probiotic was informed by prior research demonstrating its potential beneficial effects in animal models.


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To gain insights into the changes occurring in the participants' gut microbiomes, the researchers employed 16S rRNA gene sequencing to identify and compare bacterial compositions in stool samples. Additionally, they employed whole genome sequencing to delve into the functional roles of the identified bacteria.

The analysis yielded intriguing results. Microbes belonging to the Prevotella genus were found to be present in higher relative abundance among participants with mild cognitive impairment when compared to those without cognitive impairment. This suggests that the composition of the gut microbiome could potentially serve as an early indicator for mild cognitive impairment, offering a window of opportunity for interventions aimed at slowing cognitive decline.

Promising Outcomes

One of the most exciting aspects of the study was the observed reduction in Prevotella relative abundance in participants with mild cognitive impairment who received the LGG probiotics. Remarkably, this decrease in Prevotella coincided with improved cognitive scores, indicating a potential link between manipulating the gut microbiota and enhancing cognitive health in older adults.

Microbiome analysis identified Prevotella ruminicola, Bacteroides thetaiotaomicron, and Bacteroides xylanisolvens as taxa correlated with MCI. (CREDIT: Clinical Nutrition)

Aljumaah emphasizes the significance of these findings: "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." This discovery suggests that targeting the gut microbiome could be a novel approach to support cognitive health, particularly in individuals at risk of cognitive decline.

The Road Ahead

The researchers are now delving deeper into the mechanisms by which certain gut microbes, including Prevotella, influence the gut in a way that promotes brain health. Specifically, they are investigating how molecules produced by these bacteria may modulate the functionality of neuroprotective hormones capable of crossing the blood-brain barrier.

This study investigated the gut microbiome composition and predicted microbial functional pathways of middle-aged and older adults that met criteria for mild cognitive impairment (MCI), compared to neurologically healthy individuals, and investigated the impact of probiotic Lactobacillus rhamnosus GG (LGG) in a double-blind, placebo-controlled, randomized clinical trial. (CREDIT: Clinical Nutrition)

Mashael Aljumaah's outlook on the potential of these findings is optimistic: "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."

As researchers continue to explore the intricate connection between the gut and the brain, the future may hold innovative and non-invasive methods to combat cognitive deterioration in the elderly, offering a brighter and more vibrant quality of life for older generations.

Reference: “The Gut Microbiome, Mild Cognitive Impairment, and Probiotics: a Randomized Clinical Trial in Middle-Aged and Older Adults” by Mashael R. Aljumaah, Andrea M. Azcarate-Peril, Jeffery Roach, John Gunstad and Urja Bhatia, 24 July 2023, NUTRITION 2023 (abstract;presentation details).

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Joseph Shavit
Joseph ShavitSpace, Technology and Medical News Writer
Joseph Shavit is the head science news writer with a passion for communicating complex scientific discoveries to a broad audience. With a strong background in both science, business, product management, media leadership and entrepreneurship, Joseph possesses the unique ability to bridge the gap between business and technology, making intricate scientific concepts accessible and engaging to readers of all backgrounds.