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Science is now suggesting the ability of fermented foods to boost nutritional, antioxidant and anti-inflammatory properties in carbohydrate-rich foods and beverages, increase the biodiversity of good bacteria in our gut – called our microbiota – encourage the growth of our already-present microbiota, and protect against chronic, pervasive syndromes like diabetes, Crohn's disease, celiac disease, irritable bowel syndrome, and depression.
What is fermentation and why is it important
Fermentation is the transformative process where microorganisms, like bacteria and yeast, metabolize carbohydrates in foods like fruits, vegetables and grains, breaking them down and making them easier for us to digest, and often increasing their health-promoting properties.
In sauerkraut, for example, beneficial lactic acid bacteria already present on fresh cabbage begin the metabolic process of fermentation when sealed in a container with salt, creating ideal conditions for the healthy bacteria to flourish, and an acidic environment hostile to harmful bacteria.
"What's really interesting about fermented foods," says naturopathic doctor Alan Logan, "is that they carry a broad variety of bacteria with them, and biodiversity matters so that you're having a broad effect on the good bacteria in your gut."
The bacteria in our body outnumber our own cells by ten to one so it's no wonder that they play an integral and multi-faceted role in our physiology. Not only do they protect us from pathogenic microorganisms and increase the nutrient bioavailability of our food, emerging research is suggesting they play an important role in our mental health as well.
But in our over-sanitized, chronically-stressed, nutrient-poor lives, the good guys are facing an arduous battle. Antibiotics,animal protein, seafood, or contaminated fruits and vegetables knock out both healthy and harmful bacteria from our systems, as does environmental stress and the standard American diet, characterized by high-fat, high-sugar, highly processed foods, and even psychological stress, say studies.
This loss of microbial diversity and subsequent imbalance between good and bad bacteria in the gut is called dysbiosis.
Further adding to dysbiosis is the divergence from our traditional hunter-gatherer and agricultural lifestyles that had us consistently in touch with nature – literally coming into contact with beneficial lactic acid bacteria in the soil.
"When the wrong type of bacteria start becoming the norm, you get a slightly more porous intestinal lining, called intestinal permeability, and unwanted material can pass into the bloodstream, which causes a low-grade immune response and low-grade inflammation and the release of what are called cytokines," says Logan.
One study in An International Journal of Gastroenterology and Hepatology linked this inflammatory intestinal-permeability cascade to diabetes, Crohn's disease, celiac disease, and irritable bowel syndrome, and in the book Your Brain On Nature, co-authors Alan Logan and Harvard physician Eva Selhub, note that "the elevation of inflammatory chemicals called cytokines can cause depression, anxiety, and cognitive brain fog in healthy adults."
Further studies highlight other pathways "whereby beneficial microbes could influence mood" and cite exciting new research from McMaster University whose animal studies focused on the microbiota-gut-brain axis, specifically the direct line of communication from gut to brain, called the vagus nerve. "These findings highlight the important role of bacteria in the bidirectional communication of the gut-brain axis and suggest that certain organisms may prove to be useful therapeutic adjuncts in stress-related disorders such as anxiety and depression," say the study's authors.
Both cutting edge research and insight on traditional dietary patterns point to the importance of promoting and maintaining a diverse and healthy microbiota for increased physical and mental health, and fortunately there are myriad ways to help these helpful microbes flourish.
How to work beneficial bacteria into your diet
For tried and true fermented foods, look to traditional diets which include Greek yogurt, red wine, miso, kimchi, fermented fish and sauerkraut, containing a rich biodiversity of pathogen-fighting, beneficial bacteria as well as nutrients with amplified bioavailability, antioxidant and anti-inflammatory properties.
In light of promising research on fermentation's many benefits, fermented supplements are beginning to crop up on the market, like Genuine Health's Greens+ Whole Body Nutrition, for which Logan is an independent consultant. "This is the first time there's ever been a constellation of fermented ingredients brought together," said Logan of the 70-percent fermented ingredients containing fermented plant foods, fermented essential fatty acids, fermented fibre and fermented protein.
Prebiotic and probiotic supplements
Nutritional supplements containing both prebiotic and probiotic ingredients can also benefit the gut microbiota, and overall health. Prebiotics are fermentable dietary fibres (like inulin) that stimulate the growth or activity of probiotics, which are beneficial bacteria.
The Vega One Nutritional Shake contains both prebiotic and probiotic ingredients, with six grams of dietary fibre (including inulin) and one billion CFUs (colony forming units) of probiotic lactic acid bacteria (including Lactobacillus).
Play in the dirt or get gardening
In Your Brain On Nature, the authors note that the beneficial lactic acid bacteria Lactobacillus bulgaricus, found in many fermented foods, also naturally occurs in soil. "It would be fairly simple for gardeners to make incidental contact with healthy Lactobacillus while tilling the soil," say researchers.
"There's a trend for fermentation now, even Williams-Sonoma sells fermentation pots," says Logan. So why not bring it full circle and learn to ferment food that you've grown yourself. "But," he cautions, "it's an art and you have to know what you're doing."