- Fermented foods may be linked to improved cognitive performance, particularly because of their ability to influence the microbiome-gut-brain axis, according to a new review.
- Fermented foods keep the intestinal barrier healthy and strong, preventing bacteria and toxins from entering the circulation and reducing the chance of leaky gut syndrome.
- The gut-brain connection is linked to many brain functions, such as memory, cognition, anxiety, depression, and overall health.
In recent years, much research has focused on gut microbes, particularly on how they interact with the brain (microbiota-gut-brain axis). Because fermented foods are particularly known for their benefits for gut health, researchers wanted to explore how these foods might affect mental health.
A new comment was posted onNeuroscience and Behavior Reviews Different types of fermented foods, fermentation techniques, and their ability to influence the microbiota-gut-brain axis were studied. The researchers also analyzed knowledge gaps and challenges when conducting human studies.
Examples of fermented foods include:
The review states that fermented foods directly affect the enteroendocrine system, thereby affecting hormones such as ghrelin, neuropeptide-Y, glucagon-like peptide 1 (GLP-1) and serotonin. Fermented foods are rich in prebiotics and probiotics, which can increase the content of GLP-1. However, further research is needed to understand how fermented foods affect appetite and hunger.
Human studies on fermented dairy products have had mixed results on cognitive health, while observational studies have linked fermented food intake to changes in gut health and reduced anxiety.
“We know from previous research that there is a proven gut-brain axis, so this directly links diet to the brain and its behavior based on microbiome health,” said nutrition consultant and assistant professor Dr. Nicole Avena. “Ph.D. in Neuroscience from Mount Sinai School of Medicine, Visiting Professor of Health Psychology at Princeton University,” sugar free.
“I think this review does a great job of showing the history behind fermentation, and the physiology behind fermentation, and how it can be a superfood for gut and brain health,” she said.
Avina explains that our guts contain hundreds of different strains of bacteria. Everyone’s microbiome is unique, as a number of different factors influence the species and diversity within the gut. These factors range from maternal health before birth to the current environment.
“The reason food is such an important part of gut health is that it’s a tangible method we can use to diversify and enhance (or weaken) our gut flora,” Avina says. “The gut-brain axis is linked to the health and diversity of the microbiome – meaning the less diverse the diet, the more mental and brain health is affected. We know these bacteria contribute to the digestion, absorption and by-products of nutrients, thereby It has a direct impact on our mental health.”
According to Dr. William Li, MD, New York Times best-selling author, the brain and gut are connected through many pathways involving nerves and circulation. Eat to Beat Dieting: Burn Fat, Improve Metabolism, and Extend Lifeexplained.
“Substances produced by bacteria in the gut can travel or send signals directly to the brain through large nerves, such as the vagus nerve, triggering different brain activities that can alter mood, behavior, memory and cognition,” he said.
Lee continued: “From the other end, substances from the brain can travel along the nerves that start in the brain and distribute like wires to the gut. These signals can influence the gut bacterial ecosystem.”
From a circulatory perspective, microbes in the gut can produce substances that enter the bloodstream, which are then circulated directly to the brain. Likewise, chemical signals produced by brain cells can enter the bloodstream from the brain and circulate to the gut, affecting the gut microbiota, Li added.
“While research into the exact effects of bacteria-to-brain/brain-to-bacteria is still in its infancy, this gut-to-brain connection has been linked to multiple brain functions such as memory, cognition, anxiety, depression, and overall psychological functioning. Be healthy,” Lee said.
“There are many compelling correlations linking dysbiosis, or abnormalities in the composition of the gut microbiome, to depression, anxiety, dementia, Parkinson’s disease and other neurodegenerative diseases,” he added.
Fermented foods contain the bioactive substances of the original food itself (e.g., polyphenols, dietary fiber), healthy bacteria (probiotics), and the metabolites produced by these bacteria (postbiotics).
These components of fermented foods can contribute to the activity of the gut microbiome of people who eat the food, either by feeding healthy gut bacteria (stimulating their effects on the gut-brain axis) or by directly promoting gut bacteria or their products, Li explains. .
“The net effect is to help create a healthier gut bacterial ecosystem that activates brain pathways. There are many unanswered questions about the gut-brain connection, but this is the current view based on laboratory studies and human studies,” He said.
This review addresses many of the knowledge gaps and limitations in current research on gut-brain connectivity.
For example, “Studies involving single bacteria do not provide a comprehensive understanding of the effects of fermented foods on the gut-brain axis because there are a large number of bacteria, metabolites and other small molecules in the food that may play important roles,” Li said. .
Additionally, “clinical studies of fermented foods may not capture sex differences or account for the diversity of dietary, lifestyle, behavioral and genetic factors among subjects,” he added.
The generalizability of the findings is also limited by differences in how fermented foods are produced, stored and consumed in different regions. Lee added that despite these limitations, the review makes a compelling case based on scientific evidence that gut health affects brain health, which in turn affects mood and behavior.
It is also important to note that this review did not use any original data as it is a narrative review. There was no formal scoring of the research quality of individual papers, although the authors noted that the individual studies they cited had poor methodology, such as insufficient controls.
“I think one of the only major limitations is the limited number of studies using human subjects,” Avina said.
“More evidence is needed on the direct impact of fermented foods on the human microbiome and neurotransmitter research.”
— Nicole Avina