Probiotics may help slow cognitive decline

Key takeaways:

• The probiotic Lactobacillus rhamnosus GG was associated with changes in the gut microbiome and improvements in cognition.
• The findings suggest that probiotics may help slow the progression of cognitive decline.

BOSTON — Adults with mild cognitive impairment who received the probiotic Lactobacillus rhamnosus GG for 3 months had improvements in cognitive scores compared with those who received placebo, according to findings presented at NUTRITION.

The improvement in cognition correlated with changes in participants’ gut microbiome, Mashael R. Aljumaah, a PhD candidate at the University of North Carolina at Chapel Hill and North Carolina State University, and colleagues reported.

“For primary care clinicians, the key takeaway from our study is that the gut microbiome might play a significant role in the early stages of cognitive impairment,” Aljumaah told Healio. “We found correlations between certain gut bacteria, such as Lactobacillus rhamnosus GG (LGG) and various species of Prevotella, and cognitive function.”

Aljumaah and colleagues enrolled 169 community-dwelling adults aged 52 to 75 years to a 3-month, double-blind, placebo-controlled, randomized clinical trial to investigate changes in the gut microbiome and cognitive scores among those who received the LGG probiotic vs. placebo. They used 16S rRNA gene sequencing and whole-genome sequencing to analyze bacteria in participants’ stool samples.

The researchers found that Prevotella was significantly more present in participants who had mild cognitive impairment compared with those who had no cognitive impairment. Further, participants with mild cognitive impairment who received the LGG probiotic experienced a decrease in Prevotella, as well as an increase in cognitive scores.

“These findings suggest that if we can identify changes in the gut microbiome early on, when patients first meet the criteria for mild cognitive impairment, we may have an opportunity for early intervention,” Aljumaah told Healio. “Probiotics or diet changes could potentially help to manage or even slow down the progression of cognitive decline.”

However, she added that more research is needed to confirm the results “and understand how best to implement microbiome-focused interventions.”

“For now, our study underscores the importance of considering the gut microbiome when managing patients with early signs of cognitive decline,” she said.

As part of the next steps of their research, Aljumaah and colleagues are aiming to better understand the Prevotella genus, “which our initial findings suggest could play a significant role in cognitive health,” Aljumaah said.

“We’re delving into the specifics, pinpointing which species of Prevotella might influence cognitive function and the mechanisms they use,” she said. “Our particular interest lies in whether certain genetic traits or processes within Prevotella contribute to the progression of cognitive impairment. This understanding could significantly contribute to personalized medicine and shape future strategies for cognitive health management.”

References:

• Aljumaah MR, et al. The gut microbiome, mild cognitive impairment and probiotics: A randomized clinical trial in middle-aged and older adults. Presented at: NUTRITION; July 22-25, 2023; Boston.
• Could probiotics help slow age-related cognitive decline? www.eurekalert.org/news-releases/995497. Published July 24, 2023. Accessed July 24, 2023.