Cheap Supplement Boosts Brain Function in Older People

Why Researchers Are Calling It a Breakthrough

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My Longevity Experiment
February 21, 2025

The Link Between Gut Health and Brain Function in Aging

A groundbreaking study on twins has revealed that daily supplementation with protein and prebiotics can enhance memory function in individuals over the age of 60. Conducted by researchers at King’s College London, this study is the first of its kind to examine the impact of prebiotics on cognitive function in aging adults.

These findings carry significant implications, particularly because the same visual memory and learning test used in the study is also employed to detect early signs of Alzheimer’s disease.

Prebiotics and Their Role in Gut Health

The double-blind trial tested two widely available plant-based fiber prebiotics: inulin and fructooligosaccharides (FOS). These non-digestible compounds are known to support gut microbiota by promoting the growth of beneficial bacteria.

Inulin is a dietary fiber classified as a fructan, while FOS is a plant-derived carbohydrate often used as a natural, low-calorie sweetener. Both are commonly found in over-the-counter supplements and functional foods.

Study Design and Key Findings

To assess the effects of these prebiotics on cognitive aging, researchers enrolled 36 pairs of twins over the age of 60. Each twin pair was randomly assigned so that one twin consumed a daily prebiotic supplement mixed with protein powder, while the other received a placebo in protein powder.

The results indicated that the twins who unknowingly consumed inulin or FOS performed better on cognitive tests after three months. Additionally, those taking prebiotics exhibited slight changes in their gut microbiome, with an increased presence of beneficial Bifidobacterium bacteria.

Previous research on mice suggests that Bifidobacterium may help reduce cognitive deficits by regulating the gut-brain axis. These findings contribute to the growing body of evidence linking gut health to brain function.

"We are excited to see these changes in just 12 weeks. This holds huge promise for enhancing brain health and memory in our aging population," said Mary Ni Lochlainn, a geriatric medicine researcher at King’s College London. "Unlocking the secrets of the gut-brain axis could offer new approaches for living more healthily for longer."

The Role of Twin Studies in Aging Research

King’s College London houses the United Kingdom’s largest adult twin registry, making it an ideal institution to study the effects of genetic and environmental factors on health. Twin studies provide unique insights into human biology by allowing researchers to distinguish hereditary influences from lifestyle and environmental factors.

Prior research on rodents has demonstrated that high-fiber diets, including inulin and FOS, nourish the gut microbiome, fostering the growth of beneficial bacteria. Some of these microbial strains have been linked to improved cognitive function in both mice and humans, reinforcing the theory that gut health is integral to brain health.

The Gut-Brain Connection and Future Implications

The relationship between the gut and the brain is increasingly recognized as a critical factor in overall health. Some experts now refer to the gut as the body’s "second brain" due to its extensive network of neurons and neurotransmitter activity.

While the precise mechanisms of gut-brain communication remain unclear, this recent twin study suggests that consuming certain prebiotics may serve as a potential intervention for cognitive decline. However, despite improvements in memory and processing speed, the study did not find evidence of physical benefits, such as reduced muscle loss, in participants taking prebiotics.

"These plant fibers, which are cheap and available over the counter, could benefit a wide group of people in these cash-strapped times. They are safe and acceptable too," said geriatrician Claire Steves at King’s College London. "Our next task is to see whether these effects are sustained over longer periods and in larger groups of people."

The Need for Further Research

The study’s participants were predominantly female, and although researchers adjusted for sex differences in their analysis, they acknowledged potential selection bias within King’s College London’s twin cohort. Nonetheless, the findings are particularly relevant given that women are at a higher risk of developing Alzheimer’s disease.

This research supports the emerging concept that cognitive decline is not solely a brain disorder but may also be influenced by external factors, including gut health. The gut plays a crucial role in numerous bodily functions, including immune regulation and central nervous system activity. Optimizing the microbiome with prebiotics and probiotics could pave the way for innovative treatments for various age-related diseases.

As evidence continues to mount on the gut-brain axis, further studies are needed to explore the long-term impact of prebiotic supplementation on cognitive health and overall longevity.

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