FITNESS FORUM: The influence of gut bacteria on mental health

By Christie Donato

In just the past few years fermented foods and beverages have made a big comeback. Kombucha, sauerkraut, miso, kimchi, kefir and other fermented options from across the globe have officially gone mainstream, making their way into both professional and home kitchens everywhere. It should come as no surprise that the popularity of these foods comes at a time when a growing body of research suggests that the relationship between the gut and the brain is stronger than we realized. Could it be that integrating the fermented food choices of our ancestors into our modern day diet is the key to lasting gut health, and, by extension, an important component of our mental health?

Every single person’s gut is populated with trillions and trillions of microbes, most of which are bacteria. This teeny tiny ecosystem living inside every creature on Earth is referred to as the gut microbiota. Most people realize that they have miniscule organisms living inside of them, but were you aware that there are so many bacterial cells in your body that they actually outnumber human cells overall? This means that the bacteria living inside us have a significant role to play in our body’s health, and, as a general rule, the more diverse the population of bacteria in the gut, the healthier you’ll be.

The simplest way to promote your gut microbiome’s diversity is by consuming different kinds of food, which is where fermented foods come into the picture. While the process of fermentation has been around for thousands of years, and was originally used as a means of food preservation, it wasn’t until the 1900’s when scientists began to hypothesize that certain bacteria present in these foods could be responsible for the longevity of particular groups of people with a diet high in fermented foods. Far more recently, scientists have also begun to explore the links between the gut microbiome and mental health. According to the article “Fermented Foods, Microbiota, and Mental Health: Ancient Practice Meets Nutritional Psychiatry” from the Journal of Physiological Anthropology, “…the fermented foods so often included in traditional dietary practices have the potential to influence brain health by virtue of the microbial action that has been applied to the fermented food or beverage, and by the ways in which the fermented food or beverage directly influences our own microbiota.”

In some promising studies of mice and humans with depression and generalized anxiety, ingesting probiotics with the Bifidobacterium infantis strain has been shown to increase levels of tryptophan, an amino acid that promotes the production of serotonin in the body. According to WebMD, serotonin is notable for being the chemical neurotransmitter that regulates our “mood, sexual desire and function, appetite, sleep, memory and learning, temperature regulation, and some social behavior.” This is just one example, and while more research still needs to be done on the subject, there’s a real possibility that probiotics, a live yeast or bacteria species that has been added to either food or a supplement, can be harnessed to combat mood disorders like depression. Probiotics are cheaper, more available, and don’t have the side effects that an antidepressant (SSRI) does, which makes replacing them an attractive option for many.

The link between good bacteria and a healthy mind is becoming more and more apparent, which is why many people are looking to incorporate them into their daily diet, often in the form of probiotics. Foods and supplements with probiotics are a useful way to regulate gut health, but it’s important to note that as of right now, probiotics are considered a supplement, and, as such, are not currently regulated by the FDA. This means that companies are not being held accountable for what bacterial species are actually present in products with probiotics. Before you pick any old yogurt with a “probiotic” label off the grocery store shelf, do your research. The first thing to look out for is what specific bacterial species are present, you want one that has been proven to address gut health, such as Bifidobacterium or Lactobacillus. The next step is to find a company with a third-party certification, meaning they use an independent organization to test their products. The third step, of course, is to fully embrace the use of fermented foods in your home cooking, which tend to naturally include these good bacteria.