This Probiotic Reduces Mild Cognitive Impairment Symptoms (M)

The probiotic has been investigated in over 250 clinical trials.

The probiotic has been investigated in over 250 clinical trials.

Probiotics help prevent mild declines in memory and thinking skills that typically occur with age, a study finds.

Older adults with mild cognitive impairment who took Lactobacillus rhamnosus GG (LGG) for three months displayed improved cognition scores.

LGG has been investigated in over 250 clinical trials and there is some evidence it can be useful for treating irritable bowel syndrome and some other gastrointestinal issues.

Ms Mashael Aljumaah, the study’s first author, said:

“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.

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.”

Fighting memory problems

The experiment involved 169 people aged 52 to 75, some of whom had Mild Cognitive Impairment (MCI).

MCI is diagnosed when people have age-related problems with memory and thinking, but can still live independently.

People with MCI may go on to develop dementia, but some people never get worse and many improve.

Ms Aljumaah said:

“Many studies focus on severe forms of cognitive diseases such as Alzheimer’s and dementia, but these conditions are more advanced, making them significantly harder to reverse or treat.

In contrast, we focused on mild cognitive impairment, which can include problems with memory, language, or judgment. Interventions at this stage of cognitive impairment could slow down or prevent the progression to more severe forms of dementia.”

Not only did the thinking skills of participants who took probiotics improve, the results showed, but changes were measured in the gut microbiome.

Microbes in the genus Prevotella decreased as people’s thinking skills increased.

Ms Aljumaah said:

“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.

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.”

It is not yet known how or why Prevotella interacts with brain health — that is what the researchers are working on next.


The study was presented at Nutrition ’23 in Boston, MA (Aljumaah et al., 2023).

Author: Dr Jeremy Dean

Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology. He has been writing about scientific research on PsyBlog since 2004.

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