What do mozzarella cheese, pepperoni, and olives have in common? These food items may be the toppings on a pizza, but they share another characteristic; they are all fermented foods. Sauerkraut is usually what comes to mind when people think of fermented foods. Many other treasured foods like yogurt, wine, beer, sourdough bread, kimchi, salami, sour cream, Worcestershire sauce, and tempeh are also fermented foods. Humans have been fermenting foods for thousands of years as a method of food preparation and preservation, but more recently we discovered the important role that these foods play in human health.
Fermentation can be traced back 13,000 years as researchers have found beer residues in a cave in Haifa, Israel. (Liu 2018) Archeologists have also discovered pottery vessels in China from the Neolithic Period, dated around 7000–6600 BCE, that contained traces of ‘Mixed Fermented Beverages’ made from rice, honey, and fruit. (McGovern 2004) Besides wine and beer, virtually every culture has a history of its favorite fermented foods. From Kimchi and Chutneys in the East to Sauerkraut and Yogurt in the West, fermented foods offer an array of mouthwatering deliciousness. Fermentation is a great way to prepare foods for consumption due to the complex flavors that emerge in the fermentation process.
Fermentation is used to preserve foods or beverages. The process of fermentation uses microorganisms. Anaerobic microorganisms (those that can live without utilizing molecular oxygen) produce enzymes that break down and extract energy from carbohydrate molecules, and then leave behind: ethyl alcohol, lactic acid, and acetic acid. Pathogenic organisms that cause sickness in humans cannot survive in the salt used for preserving food, or in the alcohol or acid environment produced by anaerobic microorganisms. In addition to keeping harmful bacteria away, the fermentation process is void of oxygen. Oxygen and oxidating enzymes are what causes foods to break down. An environment void of oxygen that is either acidic and salty; or alcohol, are what keeps food from degrading and keeps our food preserved via fermentation.
Our ancestors used other preservation methods for foods. Drying was one method used which worked well for fruits and some vegetables. Meats were also salted and dried or smoked; but sometimes botulism poisoning from bacteria would occur. (Ray 2010) Dried foods do not always offer the palatability that fermented foods offer, so fermentation was often the favored choice. Plus, we do love our beer and wine!
Our ancestors did not know what caused fermentation from a biological perspective, they just knew that it worked to keep foods preserved. They also knew that fermented and brewed beverages provided hydration without the risk of drinking water that might be contaminated by pathogenic bacteria. The discovery of what causes food spoilage was in 1850’s when a scientist named Louis Pasteur wrote about and then substantiated via experimentation, that microorganisms cause both spoilage and fermentation of foods. (Vallery-Radot 1919) This discovery substantiated the germ theory of disease. His scientific research guided us to pasteurization, which is process the boiling of milk or beer to destroy or inhibit the growth of pathogenic microorganisms.
In addition to Pasteur’s microorganism discoveries, the 1850’s was when commercial refrigeration and canning jars were invented. Pasteurization, canning, and refrigeration are some of our modern food preservation techniques. These modern techniques have drastically changed the way that we preserve foods. These discoveries are less than 200 years old and are a mere blink of time in human history.
Another interesting fact about Pasteur’s research is that it drove the beginning phases of vaccine development. Pasteur played a key role in developing vaccines for chicken cholera, anthrax, and rabies. (Wikipedia) He observed, “if we could intervene in the antagonism observed between some bacteria, it would offer perhaps the greatest hopes for therapeutics”. (Kingston 2008) Shortly after he was able to identify microorganisms as a source of infection and sickness, penicillin was discovered, and then antibiotics were developed. Around 1940 we began using antibiotics in livestock and humans. As our understanding of bacteriology developed, we began chlorinating our drinking water. By the late 1970’s, virtually all municipal water facilities utilized chlorination as a method of reducing the harmful pathogenic bacteria.
The result of widespread use of antimicrobial agents like antibiotics and chlorine, along with advanced food preservation methods like canning and pasteurization, is that we eliminate harmful bacteria. Along with the harmful bacteria, we eliminate virtually all bacteria. This also means the elimination of commensal or helpful bacteria.
Since 2007, our understanding of the human microbiome has greatly expanded. It is estimated that over 900 different microbiota species are present on or inside humans, of which around 160 live in our gut. (Rogers) Among the many bacterial species that reside in our gut, Lactobacillus Reuteri (L. reuteri) is believed to play a key role in human health. Dr. Xin M. Luo, PhD in immunology and an associate professor of immunology in the Department of Biomedical Sciences and Pathobiology at Virginia Tech, co-authored the paper: ‘Role of Lactobacillus reuteri in Human Health and Diseases’. In this paper, she notes that L. reuteri is responsible for a number of functions in humans including: keeping our gut lining intact, producing an antimicrobial compound called reuterin that protects us from harmful bacteria, synthesizing vitamins like B-12, maintaining tissue homeostasis, protecting us against oral diseases, reducing inflammation, regulating the development of obesity, and protecting us from neurodevelopment disorders. (Mu 2018)
L reuteri is the same anaerobic microorganism that is responsible for the production of lactic acid, which causes fermentation. Fermented foods contain an abundance of this microorganism. Our changes in food preservation techniques, along with the systematic reduction of all bacteria with antibiotics and chlorination, have caused humans to have a smaller abundance of these helpful microorganisms in our guts. Studies now show that it takes at least nine months for our microbiome to recover after a treatment of antibiotics. (Yoon 2018) Anything that is antimicrobial, like alcohol or pesticides, will reduce or eliminate our gut bacteria.
Because fermented foods and L. reuteri play such an important role in human health, enhancing gut bacteria will increase our wellness. Probiotic supplements are not the answer because they can be tainted, and the supplement industry in unregulated. Including fermented foods in our daily or weekly diet is a must. It is best not to use store bought sauerkraut or other fermented foods because they are canned in sterilized and heat-treated packaging which kills the healthy bacteria. Creating fermented foods is super easy. There is an abundance of instruction videos on YouTube, and recipes all over the internet. Have fun experimenting with them while creating better health!
Kingston W ‘Irish contributions to the origins of antibiotics’, Irish Journal of Medical Science. 177: Pages 87–92, June 2008 https://doi.org/10.1007/s11845-008-0139-x
Liu, Li and Jiajing Wang, Danny Rosenberg, Hao Zhao, Gyorgy Lengyel, Dani Dadel, “Fermented beverage and food storage in 13,000 year-old stone mortars at Raqefet Cave, Israel: Investigating Natufian ritual feasting” Journal of Archaeological Science Volume 21, October 2018, Pages 783–793 https://www.sciencedirect.com/science/article/abs/pii/S2352409X18303468
McGovern, Patrick and Juzhong Zhang, Jigen Tang, Zhiqing Zhang, Gretchen R. Hall, Robert A. Moreau, Alberto Nuñez, Eric D. Butrym, Michael P. Richards, Chen-shan Wang, Guangsheng Cheng, Zhijun Zhao, Changsui Wang “Fermented beverages of pre- and proto- historic China” Proceedings of the National Academy of Sciences USA, December 21, 2004 https://www.pnas.org/content/101/51/17593
Mu, Qinghul and Vicent J. Travella, Xin M. Luo, “Role of Lactobacillus reuteri in Human Health and Diseases” Journal of Frontiers in Microbiology, Volume 9, Page 757, 19 April 2018 https://www.frontiersin.org/articles/10.3389/fmicb.2018.00757/full
Rogers, Kara. “Human microbiome”. Encyclopedia Britannica, Dec 05, 2011 https://www.britannica.com/science/human-microbiome Accessed 16 February 2021.
Ray, Frederick K., “Meat Curing” Oklahoma Cooperative Extension Report, Oklahoma State University. Retrieved 16 February 2021. http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2055/ANSI-3994web.pdf
Vallery-Radot, René (1919). The Life of Pasteur. Translated by Devonshire, R. L. London: Constable & Company. p. 79. https://archive.org/stream/in.ernet.dli.2015.173907/2015.173907.The-Life-Of-Pasteur#page/n101/mode/2up
“Louis Pasteur” Wikipedia Online, electronically published 20015–2005. Accessed 16 February 2021 https://en.wikipedia.org/wiki/Louis_Pasteur#Immunology_and_vaccination
Yoon, Mi Young and Sang Sun Yoon, “Disruption of the Gut Ecosystem by Antibiotics” Yonesi Medical Journal 59, Published Online, January 2018, Pages 4–12. https://eymj.org/DOIx.php?id=10.3349/ymj.2018.59.1.4