Unintended gardens: How the Probiotics of Home Fermentation can Expand our Immunity Beyond our Bodies, by Adam Lake

me4.jpg After burning out from a double major in biochemistry and linguistics and a year of medical school, Adam Lake took a year off to travel through Central and South America studying permaculture and herbal medicine. In 2008 he returned for his second year of medical school at Temple University in Philadelphia and helped start their alternative medicine interest group. Aside from medicine, Adam is interested in economics, rock climbing, wilderness survival, and all things food related.

After learning of Adam’s adventures with fermentation, I asked him if he would use his medical knowledge and practical experience to write a short article on the medical value of unpasteurized fermented foods. –Didi Pershouse

“Hey Adam!” my roommate Steve calls to me while looking in the fridge. I turn from the pile of dishes built up in the sink from a day or two of bachelor-pad living, and see Steve holding up a half-full container of milk. “Do you think this went bad?” Cautiously I swirl the jug a bit looking for obvious lumps. When nothing awry appears, I take a distanced whiff…but it smells more like sour cream than rancid milk.

“Huh,” I say, glancing over at the several bubbling jars next to the sink, “It’s not really bad…it’s soured instead. You could still drink it.” I take a sip to back up my guess. Nothing thrilling, just sour milk, on its way to becoming yogurt or some new cheese. The common bacteria that would tend to make milk rancid appeared to have been out-competed by tastier lactobacilli , and I suspect the sourdough and lacto-fermenting oat cultures next to the sink are the cause. I make a mental note about that, as this is the first kitchen I’ve lived in with so many fermentation projects going on.

A few months prior, I had run into a book by Sandor Katz called Wild Fermentation, which appealed to me for several reasons. Katz addressed the unease of those of us who look at our modern world and think: it hasn’t been this way forever, and also wonder, having lost our basic survival skills, what will we do if it doesn’t stay this way? (How did we ever live without cell phones, the internet, the printing press or American cheese singles anyway?) He addressed this question in respect to refrigeration and other aspects of our modern food-ways, showing that not only are fermented foods safe to prepare and eat, they are essential to our health.. Katz got me excited about the prospect of fermentation, making it seem easy, and showing that I could create fermented foods—such as sauerkraut, kimchee, yogurt, sourdough bread and beer—without the laboratory sterile techniques insisted on by many home brewing instructions I had read.

Katz and Sally Fallon, (author of Nourishing Traditions) revisited some research done in the 1930’s by a disenchanted dentist named Weston Price who wondered how humans could have made it so long without dental care. His research led him to look at populations of people in various parts of the globe who were still relatively untouched by modern life, and yet had perfect jaw structures and teeth without any decay. In trying to discover what was so different about their lives that made dental care unnecessary, he realized certain commonalities about the foods that were eaten. Among his findings he noted that people who ate foods preserved through fermentation tended to have near perfect oral health, despite their routines being devoid of anything close to twice-daily brushing and flossing.[1]

Two hundred years ago, all food was either raw, (up to the moment it was cooked), salted, dried, or fermented. In 1809, French confectioner Nicolas Appert invented canning, winning a government-prompted contest to produce a safe and inexpensive means of preserving food. The growing size of armies overwhelmed supply chains that had been sufficient in previous wars, and provided the impetus for the contest.[2] Canning took off over the next century, as it not only allowed people an easier way to save summer foods, but also allowed large businesses to ship more types of food long distances and store goods in warehouses without fear of spoilage.

The blessing of canning has not come without its negative effects on culture and health. Culturally, canned goods have indicated a degree of affluence, thus, as parts of the world modernize, canned goods have replaced traditional fermented foods, and fermentation traditions are being lost the world over.[3] The intense, high-heat pressure cooking of canning also breaks down a percentage of the vitamins present in the food while often adding sugar or salt as an additional preservative.

This is in contrast to many fermented foods where the levels of accessible B vitamins are much higher than before fermentation. Proteins and complex carbohydrates, being partly digested by the fermentation process, are more easily absorbed, while toxins and anti-nutrients (such as phytic acid, a chemical in many beans which blocks mineral absorption) are reduced.[4] Botulism, the fear of home canners everywhere, can only grow in the conditions set up in canning. Clostridium botulinum, the ubiquitous bacterium that causes botulism, requires its environment to be free of competition, a pH greater than 4.6, and an oxygen-free environment.[5],[6] These are the conditions set up by the canning process, which, if the food was fermented, there would be competition from other bacteria and a build up of lactic acid or alcohol, thus preventing botulism.

The other day my kombucha (a type of lacto-fermented tea) became infected. This puzzled me as I had heard kombucha is pretty hearty and resistant to infection if there are proper nutrients available, which there were. I began to poke around to find a reason why it had gone south. I soon realized that the smelly recycling container[7] was just on the other side of the closet from the kombucha, and the infection smelled vaguely like it. The natural defenses we had developed in our apartment had folded, and who knew what this new bacteria was or how it related to humans? As medical school had started again, our fermentation projects had died down a bit, and our population of beneficial bacteria had gone untended as if weeds had taken over our garden. Only this garden is inhaled with every breath and lightly sprinkled on all we touch and consume.

Recognizing the ubiquity of bacteria in the world, the scientific community has begun to take more than a passive interest in probiotics (such as those found in yogurt), and in some bacteria’s positive effects on health[8]. There has been evidence of certain probiotic formulations having great efficacy in treating diarrhea related to antibiotics, rotaviruses, irritable bowel syndrome,[9] and traveler’s diarrhea..[10] Food allergies,[11]atopic dermatitis,[12] eczema,[13] seasonal allergies,[14]and respiratory infections[15] have also been prevented or treated with probiotics. (With these positive reports, it should be noted that probiotics have been found to do more harm than good in critically ill patients.[16]) Also, I should mention that these studies focus on very specific strains of each bacteria (e.g. Lactobacillus fermentum strain VRI-003), and not a hodgepodge of passively selected wild bacteria that might be found, say, in our kitchen. However, while the idea that exposure to bacteria while in a healthy state helps develop the immune system is not new, some studies are reevaluating population studies with this in mind. A Swedish study noted that “focus has switched from searching for environmental risk factors towards an interest in factors that could induce and maintain immune regulation and tolerance to allergens,” and suggested that probiotics may be useful in aiding immune system function[17]. This research focused more on children’s developing immune systems, but I couldn’t help but put this in context of the apartment’s ecosystem.

Researchers are finding that the benefits of fermented foods extend further than fresh foods, new flavors, or having milk sour into a still-useful state instead of turning rancid. Indeed, I have become much more aware of the ecosystem in the apartment, beyond just noticing mildew on a shower curtain.

All of us farm bacteria; we affect their growth in and around us, either intentionally or not. We select resistant strains by using antibacterial products, we tend to eat cooked foods much more often than raw foods, and we pasteurize our milk, sauerkraut, honey, miso, and sometimes even yogurt. Few of us intentionally spread beneficial bacteria through the air of our homes or the surfaces of our guts. Yet this element of our immediate ecosystem may come to be more important to acknowledge than we currently imagine.


[1] Katz, Sandor. The Revolution Will Not Be Microwaved. P 168-70.

[2] Canning. http://en.wikipedia.org/wiki/canning. 09 Aug 2008.

[3] Fermented and vegetables. A global perspective. http://www.fao.org./docrep/x0560e/x0560e13.htm.

[4] Fermentations in world food processing. Comprehensive reviews in food science and food safety. Vol. 1 2002. p29-30.

[5] http://www.who.int/mediacenter/factsheets/fs270/en. Aug 2002

[6] Clostridium botulinum. http://en.wikipedia.org/wiki/clostridium_botulinum. 10 Aug 08.

[7] Side note: Philly only has recycling twice a month, so if you forget once, then you have a month’s worth of recycling around. Our recycling is not typically smelly.

[8] http://www.ncbi.nlm.nih.gov/pubmed/10943631

[9] http://www.ncbi.nlm.nih.gov/pubmed/18616132

[10] http://www.ncbi.nlm.nih.gov/pubmed/17053425?dopt=AbstractPlus

[11] http://www.ncbi.nlm.nih.gov/pubmed/18560300

[12] http://www.ncbi.nlm.nih.gov/pubmed/18284263?dopt=AbstractPlus

[13] http://www.ncbi.nlm.nih.gov/pubmed/18560300

[14] http://www.ncbi.nlm.nih.gov/pubmed/18510694?dopt=AbstractPlus

[15] http://www.thecamreport.com/2008/02/18/the-benefits-of-probiotics-in-endurance-athletes/

[16] http://www.mja.com.au/public/issues/189_03_040808/letters_040808_fm-7.html

[17] http://www.ncbi.nlm.nih.gov/pubmed/18196956

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