Probiotic may boost cognitive function in healthy older people: RCT

Data from the randomized, double-blind, placebo-controlled trial revealed that eight weeks of supplementation with the probiotic was also associated with increases in levels of beneficial gut bacteria and decreases in the abundance of bacteria related to cognition impairment.

“This study supports probiotics as a strategy to promote healthy aging and advances cognitive aging research,” ​wrote scientists from the Key Laboratory of Functional Dairy at the China Agricultural University in Nutrients​.

Gut-brain axis​

The study adds to an ever-growing body of science supporting the microbiota-gut-brain axis is a bi-directional interaction between the gastrointestinal tract and the nervous system.

Sixty healthy older people were recruited and divided into two equal groups: One group received the BB68S probiotics at a daily dose of 50 billion CFUs, and the other group received placebo for eight weeks. Fifty people completed the trial.

The researchers used the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), which contains 12 cognitive items divided into 5 global domains, including immediate memory, visual space/structure, language, attention, and delayed memory.

Results showed that the probiotic group showed significant improvements in total RBANS score functions, increasing the global score by almost 19 points more than the placebo group.

Among the 12 items, significantly greater improvements were recorded in seven: list learning, story memory, figure copy, line orientation, coding, story recall, and figure recalls. In addition, significantly higher increases were observed for four of the five domains, with only language not significantly different between the groups.

Analysis of the composition of the gut microbiota showed that the probiotic group experience increases in the relative abundances of beneficial bacteria, including Lachnospira, Bifidobacterium, Dorea,​ and Cellulosilyticum​.

These strains have been implicated in better outcomes related to anxiety, depression, Parkinson’s disease, psychiatric disorders, and Alzheimer’s disease, said the researchers.

On the other hand, BB68S supplement also decreased the abundance of bacteria related to cognition impairment, including Collinsella, Parabacteroides, Tyzzerella, Bilophila, unclassified_c_Negativicutes, Epulopiscium, Porphyromonas,​ and Granulicatella​.

These strains have been linked to a range of detrimental effects, including inflammatory diseases, neuroinflammation, induction of depression-like behavior, and metabolic disorders in patients with postpartum depression, the researchers explained.

Promoting healthy aging​

“This study included subjects with diverse education levels and used highly sensitive screening tools specifically for different levels of education,”​ they said. “We strictly and effectively evaluated cognitive function and measured the significant effects of probiotics on cognitive function with a short-term intervention among the healthy elderly.​

“In conclusion, our research showed that ​Bifidobacterium longum BB68S could improve cognitive function and has a beneficial regulatory effect on the gut microbiota in healthy elderly individuals. This study provides some evidence supporting probiotics as an alternative strategy to advance cognitive aging and promote healthy aging.”​

Source: Nutrients​​
2023, 15​(1), 51; https://doi.org/10.3390/nu15010051​
“Probiotic​ Bifidobacterium longum BB68S Improves Cognitive Functions in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial”​
Authors: S. Shi, et al.