Fermented foods have a long history—their original use was to extend preservation to prevent spoilage. The most common examples in the United States are yogurt and cheese. Other common fermented foods include kefir, kombucha, sauerkraut, tempeh, natto, miso, kimchi, wine, beer, cider, and sourdough bread.
The general process of food fermentation involves microorganisms, such as yeast (e.g., saccharomyces cerevisiae) and bacteria (e.g., Lactobacillus), that metabolize foods such as the starch and sugars in plant products to produce organic acids, carbon dioxide, and alcohol in an anerobic condition. The byproducts of alcohol and organic acids increase the acidity of the food and prevent the growth of other microorganisms. There are two main types of fermentation. The first is naturally occurring fermentation, also known as “wild ferments” or “spontaneous ferments.” This is the action of microorganisms present in raw food, such as sauerkraut, kimchi, and various fermented soy products. The second type of food fermentation is using starter cultures, also referred to as “culture- dependent ferments,” which are added to raw foods, such as in kombucha.
The fermentation process can be applied to most any food that contains plant and animal materials. The popularity of fermented foods is global, and the types depend on the region. In South and East Asia and Southern India, fermented legumes, vegetables, fish, and meat are common. In East Asia, Northern India, Europe, and North America, fermented dairy, meat products, and cereals are more common. In the regions of Africa and South America, inhabitants regularly consume fermented seeds, legumes, milk, and meat products.
The consumption of fermented foods has a modulating or balancing effect on the gut microbiome. Fermented foods them-selves contain a large and diverse microbiome. Several studies have been conducted that demonstrate a healthier microbiome diversity in people who consume fermented foods as compared to people who do not. Many but not all of these studies were done with fermented dairy products.
Another benefit of fermented foods is that they increase poly-phenol bioavailability. As I stated earlier in this chapter, polyphenols support the growth of healthy flora. In addition, fermented foods increase the production of SCFAs, when fiber is broken down by microbes. The SCFAs also support a healthy gut micro-biome and intestinal mucosa. One example of a SCFAs produced by fermentation is acetate. Vinegar is an example of a fermented food that contains high levels of acetate. Various cheeses are also sources of SCFAs.
Researchers have shown that fermented foods are more easily digested, as they partially digest protein by producing enzymes that break down food. Moreover, fermented foods release bioactive peptides, which have health benefits. They also reduce com-pounds that prevent the absorption of nutrients. And lastly, The Journal of Nutrition reported that studies suggest that fermented food consumption supports metabolic and immune-mediated diseases.
Conclusion
I recommend consuming two or more of the fermented food products listed (with the exception of alcohol) on a regular basis. If you are dairy sensitive, there are numerous non-dairy fermented products available on the market. For example, most mornings I consume coconut or macadamia nut yogurt.
Adapted with permission from Dr. Stengler’s bestselling book The Holistic Guide To Gut Health (Hay House Publishing)
