Élie Metchnikoff, a late 19th century Russian biologist, is attributed as the first to theorize that health benefits could be derived from manipulating the bacteria in our gastrointestinal tract. Today, this has become a focused area of research and a huge industry with the development of beneficial bacteria in the form of a pill known as a probiotic. Though, while the idea may be relatively new (if you consider late 19th century “new”), the ingestion of beneficial bacteria is not.
Fermented foods are the traditional form of the modern probiotic and they have been around for a long time. Originally, food was fermented more for the sake of necessity, rather than for any possible health benefits. Since, we didn’t always have convenient refrigeration to preserve foods, our ancestors had to be a little more creative. Hence, the development of fermentation as a means of preservation. Sauerkraut wasn’t always just a topping for your hot dog.
Sauerkraut was first developed by the Chinese over 2,000 years ago where it was used as food during the non-growing season. This is a common traditional use of fermented foods – a way to prevent spoilage of food through fermentation which creates an acidic environment that both preserves the food and will only permit the growth of certain bacteria that can survive in that environment. This allows a food to be ingested far beyond it’s typical spoilage date and provides a source of food during times of scarcity. The Chinese used rice wine in making sauerkraut, whereas, when the dish was adopted by the Germans, they used a dry curing technique utilizing salt. The end result is similar – cabbage partially preserved in an acidic environment. Modern pickling also uses the acidic environment for preservation, but often forgoes the fermentation by using vinegar instead.
What other traditional fermented foods can you think of? Kimchi is a popular fermented dish developed in Korea. Soy sauce and miso are another fermentation of Chinese origin utilizing the soybean. Tempeh, another soybean derivative, utilizes a fungus during the fermentation process rather than bacteria. You’ve likely heard of some others as well, such as kefir, kombucha…and maybe beer? But, the most common and popular fermented product (aside from beer) is probably yogurt.
Yogurt is thought to have originated in Anatolia – in part of what is now Turkey – sometime around 500 BC. The goat herders would preserve their milk by drying it in the sun and transporting it in goat-skin or sheep-skin bags. It is thought that the bacteria contained on the goat or sheep skin contributed to the spontaneous fermentation, and subsequent thickening, of the milk, turning it into yogurt. In modern times, we have a somewhat updated method of making yogurt where milk is heat pasteurized and bacteria are added to ferment and thicken the milk. This illustrates one of the main differences between modern fermentations using specific strains and wild-type fermentations. In wild fermentations there are going to be a larger variety of bacteria or yeast that are derived from the local environment.
Unfortunately, there has been a significant decline in the use of fermented foods as the necessity for them has decreased. What we see instead are the continued usage of some of these foods, albeit in more modern, and sometimes, more adulterated forms. For instance, most sauerkrauts you purchase at the grocery store hold little value as a fermented food as they have been pasteurized. This kills all the live bacteria, discontinues fermentation and thereby dramatically decreases the health benefits of the food. In another example, soy sauce, traditionally derived through a soybean fermentation or a soybean and wheat fermentation, is now often produced via acid hydrolysis – a process that necessitates the addition of a variety of additives, such as caramel color and corn syrup, to achieve a similar color and taste profile.
We’ve discussed a variety of probiotic or fermented foods, but I’ve yet to elucidate the first probiotic that many of us are exposed to – our mother’s milk. That’s right, human breast milk is actually the first probiotic many of us ingest. Breast milk has been shown to contain various strains of bacteria, such as Lactobacillus fermentum, which may aid in the development of a healthy gut flora in the infant. Breast milk is also known to contain prebiotics – nutrients that promote the growth of beneficial bacteria. This is likely part of the reason that children that have been breast fed have a different balance of gut flora when compared to formula fed children.
To what degree fermented foods and probiotcs permanently influence the makeup and diversity of our own gut flora is not well established. We do know that many of these bacteria survive transit through the stomach – especially various Lactobacillus strains – and we do know that many of these bacteria have beneficial effects on our health. Some studies have also shown that ingestion of probiotics can lead to more stability and diversity within the microbial community in the gut. But, whether these health effects are only transiently experienced during administration of a probiotic or whether they can lead to more permanent alterations of our gut flora is still unclear.
That doesn’t mean, however, that we can’t use probiotics to our benefit. Even if regular ingestion of fermented foods is only beneficial by helping to maintain stability and diverstiy of our intestinal flora, this can be a huge benefit. After all, some chronic diseases are associated with a decrease in bacterial diversity in our gut. Research is also providing insight into the possible targeted benefits of specific species and strains of probiotic bacteria. This is where there may begin to be a benefit to using modern probiotic supplements over traditional wild fermentations. Modern probiotic supplements can provide a predetermined formulation of specific bacterial strains that are known to provide a desired effect. In this way, probiotics can be used to treat illnesses in a targeted way based upon the specific benefits each bacterium may provide.
After all that has been said, we have to remember that research on probiotics and our gut flora is still in its infancy. We still have much to discover in terms of the effects of various known bacteria and in terms of discovering new probiotic strains. As a general health recommendation, however, I recommend the ingestion of fermented foods or a low-potency probiotic on a regular, daily basis. This is because of the strength of research showing the benefits of probiotics, the safety associated with probiotics and the history of traditional use of fermented foods.
What are your thoughts? Do you have experience with fermented foods? Or maybe you’ve experienced the benefits of probiotics. Share your thoughts in the comments section below.