Probiotics and Diet for Better Cognitive Function

• A recent review examines how modifying the gut microbiome can promote brain health.
• It specifically looks at probiotics, prebiotics, dietary modifications, and fecal microbiota transplants (FMT).
• The authors suggest that adjusting the gut microbiome may help slow cognitive decline and enhance brain health.
• This may be attributed to diminished inflammation in the brain, changes in neurotransmitter signaling, and increased levels of microbial metabolites.

In today’s fast-paced digital age, it’s wise to approach popular nutrition trends with caution. Much of the information circulating on social media can be misleading or outright incorrect.

However, the importance of gut health is underscored by a growing body of evidence supporting its crucial role in overall well-being.

A newly published review focusing on probiotics and cognitive health contributes to this expanding knowledge base. The study can be found in the journal Nutrition Research.

The authors acknowledge the need for further research, yet their findings are encouraging. They indicate that modifying the gut microbiome may assist older adults experiencing early cognitive decline in enhancing their cognitive abilities.

This field of study is still evolving, and there is significant work ahead, but they conclude that “microbiota modulation represents a promising therapeutic avenue that complements existing pharmacological and lifestyle strategies.”

Just a few decades ago, the idea that gut bacteria could play a role in slowing cognitive decline or fostering mental health would have seemed implausible.

Today, this notion is increasingly accepted in mainstream science. While it will take considerable time to unravel these complex relationships, the connection is well recognized.

Our bodies harbor trillions of microbes that assist in digestion, synthesizing vitamins, and producing various compounds essential for our health.

Research now indicates that these microbes also communicate with the brain through several pathways, collectively known as the gut-brain axis.

One such pathway is the vagus nerve, which connects the gut to the brain. Additionally, compounds like short-chain fatty acids (SCFAs), produced during fiber fermentation by bacteria, also play a role in this communication.

SCFAs can stimulate the vagus nerve directly or enter the brain via the bloodstream.

As we age, cognitive functions naturally tend to decline. Some individuals may experience a more rapid deterioration, which can progress to dementia.

With an aging population, identifying risk factors and lifestyle changes that could mitigate this decline is becoming increasingly critical. Some researchers are exploring the potential of gut bacteria.

Probiotics are live microorganisms that can provide health benefits when consumed in sufficient quantities. These can be found in various forms, including pills, beverages, and even toothpaste.

While there is some evidence that commercially available probiotics can support health, it is generally limited, particularly among healthy individuals. They tend to show effectiveness only in specific cases, such as antibiotic-associated diarrhea.

It’s essential to recognize that human gut microbiomes are incredibly diverse, and each person has a unique composition.

Even identical twins, who share identical DNA, have different gut microbiomes, proving that simply adding a few strains of probiotics is unlikely to yield noticeable effects for everyone.

This doesn’t render probiotics ineffective. The ongoing research continues to reveal specific species, strains, or dosages that might provide targeted benefits.

In addition to probiotic-rich foods and drinks, other strategies are gaining popularity. For instance, prebiotics serve as nourishment for beneficial gut bacteria.

Incorporating more prebiotics, such as dietary fiber, can promote the growth of favorable gut bacteria.

The recent review evaluates various methods for supporting cognitive health in older adults, including probiotics, prebiotics, dietary changes, and FMT, while also examining how these strategies may shield cognitive health.

This review draws from 15 studies across 10 countries, encompassing over 4,200 participants aged 45 and older. Here’s a summary of their findings:

These include essential nutrients such as B12, folate, choline, and methionine, which support vital functions like gene expression and energy production.

The authors concluded that dietary modifications could reshape the gut microbiome, boost SCFA production, and stabilize neurotransmitter networks.

These changes can foster cognitive health and reduce inflammation in the brain, a significant factor in both mental health disorders and cognitive decline.

The review indicates that probiotics and synbiotics may enhance verbal fluency and executive function, which encompasses working memory and cognitive flexibility.

Additionally, these interventions can diversify the gut microbiome, a sign of microbiome health, while also affecting neurotransmitter pathways.

Research on FMT is still limited compared to other interventions, but the authors find the early results “preliminary yet striking.”

The included study involved individuals with Alzheimer’s disease, indicating that FMT led to a more rapid shift in the gut microbiome compared to probiotics, synbiotics, or dietary changes.

Notably, the study also measured improvements in cognitive functioning and other indicators of cognitive health. Further research is required to validate these findings.

The conclusions from this comprehensive review are optimistic. They suggest the potential for modifying the gut microbiome to slow dementia and maintain cognitive sharpness with age. However, we are still in the early stages of this research.

The included studies tend to be smaller and of shorter duration.

Currently, commercially available probiotics are not selected solely based on their health benefits but rather for their safety in human consumption. Hence, while some probiotics might promote brain health, they may not be on the market.

Furthermore, FMT is not readily accessible, placing more emphasis on dietary interventions, which we can better manage ourselves.

Medical News Today consulted with Federica Amati, PhD, MPH, RNutr, regarding optimal dietary practices for gut microbiome health.

Amati, a medical scientist and public health nutritionist at the School of Public Health, Imperial College London, shared insights on diet’s effect on gut health.

“In the U.K. and U.S., many individuals do not consume sufficient fiber, which directly impacts gut microbiome health. Without fiber, gut bacteria lack essential nourishment,” she explained.

Fiber is present in nearly all plant foods, and Amati recommends eating 30 different types of plants weekly. “This is important because various types of fiber cater to different microbial preferences. A diverse plant intake ensures all beneficial microbes are supported,” she emphasized.

Additionally, she suggested minimizing the consumption of ultra-processed foods, which lack adequate fiber to benefit “good” microbes and contain numerous additives that can harm microbial health. Their high sugar and fat content can also promote the growth of “bad” bacteria.

“Fermented foods are also an excellent choice. They naturally contain probiotics, often in greater variety than commercially available supplements. Fermented vegetables, like kimchi or sauerkraut, are particularly beneficial as they are both fermented and plant-based, making them natural synbiotics.”

– Federica Amati, PhD, MPH, RNutr