Improving the gut-brain connection
Alan C. Logan, ND
An exciting area of research is showing that fermented foods benefit gut microbes. And a healthy gut microbiome may influence our mood and our brain health!
The brain has been described as medicine’s “final frontier.” In some ways, we know more about distant planets than we do about the inner workings of our own brain: a complicated network of billions of neurons. One major pathway to the final frontier runs through the gastrointestinal ecosystem and its microbes. A decade ago, the idea that gut microbes may contribute to mental health and complex brain-related disorders was laughable—at least in mainstream thought. Today, entire neuroscience conferences revolve around this topic, and that laughable idea has created a paradigm shift in neuroscience.
Many newly discovered mechanisms show how gut microbes influence brain health. These microbes communicate directly with the brain via nerves in the intestinal tract. Indirectly, gut microbes communicate with the brain by influencing circulating immune chemicals that can compromise normal brain communication and mental outlook. Moreover, intestinal microbes dictate the absorption of many important brain nutrients.
Healthy, diverse communities of gut microbes protect the intestinal lining, preventing this critical barrier from becoming porous to unwanted material, including bits of broken-down microbes. If these undesirable gut-derived agents pass through the intestinal lining into the bloodstream, they can compromise mood.
Until recently, the consequences of intestinal permeability (also known as leaky gut) were considered a naturopathic fairy tale—but no more. Dysbiosis, the loss of healthy microbial ecosystems, and increased intestinal permeability are fuelled by highly processed Westernized diets and excess physical and/or mental stress.
Fermented foods and fermented natural health products are centre stage in this unfolding conversation, representing an obvious intersection between nutrition and protection of the intestinal ecosystem diversity. Some microbes from fermented foods such as kimchi have been shown to elevate nerve cell-protecting chemicals in animals. In humans, fermented food consumption alters brain signalling and stress hormone production in ways that might support stress resiliency.
These products also hold much promise, because during fermentation the action of microbes can transform food products for the better. For example, amino acids from dietary protein sources and antioxidants from colourful plant foods can be absorbed better, and their nutritional content is potentially enhanced. Fermentation can produce brand-new peptides and plant chemical structures that may, in turn, provide benefits for mood and brain health. In addition to the enhanced nutritional value, regularly consuming fermented foods and/or supplements may turn out to have many collateral health benefits for the brain.
Although many questions remain, microbes and nutrition are, indeed, taking us to a new dimension.