Humans have been consuming fermented foods for thousands of years, but there was no widely accepted scientific definition until recently. In 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) enlisted a panel of thirteen experts from a wide range of disciplines to answer a specific question: What does the term “fermented foods'' even mean?
The panel’s task was to agree on a definition. Failure was not an option. In the press release following the decision, Mary Ellen Sanders, the Executive Science Officer of ISAPP, explained the importance of this new definition. “To date, different people have had different ideas of what constitutes a fermented food,” she said. This mixed messaging simply could not continue a moment longer. “The new definition provides a clear concept that can be understood by the general public, industry members and regulators,” Sanders concluded. What a relief.
In order to reach a consensus, the panel of experts contemplated answers to burning questions like, what is fermentation? Are fermented foods and probiotics the same thing? Do fermented foods have health benefits? Ultimately, they determined that fermented foods are “foods made through desired microbial growth and enzymatic conversions of food components.” This scientific-sounding definition becomes easier to digest when we take a look at how the panel answered their burning questions.
So, what is fermentation?
The definition of fermentation requires that microorganisms are active during the fermentation process, but does not require microorganisms to be alive in the final product. For example, shelf-stable fermented foods like pickles and jarred sauerkraut do not contain live microbes. This is because the process of preserving these foods to be stored at room temperature kills off the microorganisms. Sourdough bread is another example, live cultures are active in the dough, but do not survive the oven.
The experts included the word “desired” before “microbial growth” to distinguish fermented foods from spoiled food. Spoiled foods also contain microbial growth, but not in a good way.
Are fermented foods and probiotics the same thing?
Nope. According to the ISAPP, probiotics are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” Therefore, some fermented foods contain probiotics, but not all do. For example, probiotic yogurt commonly used for digestive health is a fermented food that contains probiotics. Jarred sauerkraut is also a fermented food, but it does not contain live microbes and therefore does not contain probiotics.
Do fermented foods have health benefits?
It depends. There are a wide variety of fermented foods, ranging from chocolate, to kimchi, to coffee. Of course, by definition, fermented foods that contain live probiotics have demonstrated health benefits. Consumers can parse out which fermented foods contain live microorganisms and which do not by looking for the words “contains live cultures” on the label. However, just because a fermented food contains live microorganisms, that does not automatically mean it contains probiotics. A fermented food that contains live microorganisms is only a probiotic if the “microorganisms have been tested and shown to provide a health benefit.”