How Should We Think About Fermented Foods and Health?
I got my start in fermentation at a young age. I remember it well, it was a hot early summer day in Toronto, where I was born and raised. I was still in elementary school at the time, but old enough to feed myself breakfast and set out on my day on my own. As such, my parents had already left for work and my sister to Junior High at another school. I’d poured myself an extra-large bowl of Honey Nut Cheerios with eyes bigger than my stomach that morning, and at the point my morning cartoons were wrapping up, I thoughtlessly left my unfinished bowl of cereal milk, with its small archipelago’s worth of “o”s on the kitchen counter. Not thinking anything of it, I headed out the door of the apartment to catch the bus and spent an uneventful day at school doing all the things kids normally do on a hot summer day. But it was upon my return home at the same time as my mum, that the day’s most interesting yet slowly protracted event revealed itself.
At my mother’s side, just as she was tidying the kitchen before she got to fixing dinner, she spotted the bowl left out since the morning next to the sink. “Dayvid…” she muttered in her typically annoyed Canadian/Caribbean accent, punctuated by a telling sucking of her teeth. She motioned to it, implying that I should clean up after myself. As I reached for the bowl with both hands, from the low angle of attack over the counter afforded by my 9-year-old body, my thumb jerked the spoon. But with such a simple motion, I knew something was amiss. The spoon pushed back. It was sitting in something, viscous? With the windows closed all day in our family’s modest 2 bedroom, my breakfast had been transformed. I picked the spoon up, and watched the cereal milk trail off it in broken clumps. “Mummy! Look! Why’s it like this?” My mother, never one to fuss about, stuck her pinky finger in, pulled out a white dipped fingertip, smelled, then tasted, then proclaimed, “You made yogurt!”
But… how?
Without a second thought, the bowl was promptly whisked over to the sink and dumped. My mother clearly had no time for such trivial things and was probably exhausted from her long day at work. She just wanted to start prepping the chicken for dinner, not clean up after her precocious, hopelessly inquisitive, and hopelessly forgetful son. The unplanned, home schooled science experiment had terminated. And while the causal connection was established, no further underlying principles were elucidated to me at all. All I had to work with was: leave milk out, get yogurt… sometimes.
The pasteurized milk stored in 1 liter bags in my fridge surely hadn’t brought these microbes to my milk bowl. I had. Our warm, humid apartment served as the incubator. The cereal bowl as the urn. The microbes living in my mouth, when transferred from mouth to spoon to the bowl, did the exactly what they were born to do in their new environment. Be fruitful and multiply.
There are two lessons to be gleaned from this story that I want to dig into in this talk.
First, there is a certain inevitability about the introduction of life from outside the bowl to its inside.
An organism can only be said to be consuming “sterile” food, void of life, under the most extreme forms of artifice (I’m sure Suzanne will dig into the fascinating requirements of germ free mice in her talk). For most everyone any everything on Earth, the boundaries of a body are fuzzy, amorphous things. Hardly the hard silhouettes Parisian runways would have us think we are. We’re in a constant dialogue with the world around us. Shedding our own cells from our bodies as we leave a cloudy aura of ourselves everywhere we go. Meanwhile, we’re simultaneously stopping to pick up hitchhiking life just about everywhere we go, by foot, bike, or bus. You don’t take just public transport, you ARE public transport. The life upon us explodes in numbers at a moment’s notice any time it’s given the chance, or rather, given an environment. Humans, it should be noted, along with a handful of other animals, have gotten pretty darned good at making sure that such requisite environments aren’t at all left up to chance.
Which bring us to the second point. If it hasn’t yet occurred to you, it should also seem a curious lesson that an 8 year old child could run an unplanned, home schooled science experiment, and converge on the successful results of Tibetan yak herders who, thousands of years prior, mastered analogous practices transforming the milk of their woolly pack animals into nutritious, delicious, concentrated, and lasting yogurts and butters, and still do to this day..
Sure, a simple ferment like yogurt can be your breakfast (on purpose or otherwise). But by examining why something as innocuous as yogurt sits at the intersection of these two natural phenomena — lets call them spontaneity and persistence — an image of fermentation’s role in human health begins to resolve. At first, they might seem like spurious footnotes. But the underlying impellers tell us much about not just humans, but any organism requires to survive in a world hell bent on tearing them apart from the moment they’re born. Like Bob Dylan says, if you ain’t busy being born you’re busy dying. That said, most of us would probably like that busy work to take as long as possible, and no less, be as gentle a ride as is permissible. With that, let’s backtrack into my youth some 30 years, when I was much less occupied with my inevitable death than I am now, as I near middle age.
All of our mouths serve as a repository for the bacteria that constantly encroach upon the ramparts of our corporeal being. For all the talk of the importance of the gut microbiome, we should not forget that the gut isn’t just one thing. It’s a system of connected organs that runs from nose to tail, so to speak. Your G.I. tract starts with your mouth. The mouth is our main portal to the world around us, or rather, the world’s main portal to us. And also, as we’ll see, it’s a fairly good synecdoche for a lot of different lessons on host/microbe interactions, that we’re primed to understand the consequences of from a young age, even if we don’t learn the details.
From the moment we’re born, as soon as we start to breath and cry, hell, even before we ever latch onto our mother’s breast open our eyes and call the big, bright, expanse of the Earth our home, lactic acid bacteria call our mouths their home. After all, how could such mesophilic anaerobes ever resist the opportunity to colonize a mouth? It feels almost like they were made for it. It has everything they need: warmth, wetness, nooks and crannies void of oxygen, and if all’s going well for their hosts, a constant supply of food. Better than three hots and a cot if you ask me. It’s also recently been discovered that the human immune system is suppressed in the first few months of life specifically to allow for beneficial microbes to colonize our bodies, and acquaint ourselves with them. But there is a yin and yang to their occupation. They aren’t exactly invited, but we’ve evolved (both biologically and culturally) at once to tolerate but also require their presence. Now, this is a curious proposition.
Think about it. Imagine installing a security system on your house to keep you and your family safe. One day you come home a fiendishly clever burglar chilling on your sofa. He’s managed to disable the alarm system with his computer wizardry skills, and now that he’s in, of all the precious things he could have stolen in your well curated home, he’s raided the fridge, and is making sandwiches for himself, leaving a mess in the kitchen in the process. And living room. And when he goes to the toilet, he doesn’t even flush. No, this uncouth slob leaves doody duty to you. Yet, for all this inconvenience, you don’t kick him out. You just continually navigate around him, even as he takes up more and more space. You tolerate him. Why? Well, on the news last night, the lead anchor put out a community wide warning in response to a string of vicious and violent home invasions. You heard rumours of neighbours a few block over being assaulted by the perp just last week, funny games style. Yet, somehow, you feel at ease because of the non violent criminal sat in your living room. He’s been to prison once before. He knows how to fight. He’s not threatening you. But you know that while he’s up late at night with the glow of infomercials bleeding through the window onto the street, the real threats feel threatened themselves. Your home is no longer an easy target. The axe murderers leering in from the bushes asks themselves, “why take the fight?”
This oddly beneficial (if tenuous) partnership takes place in your mouth, but also deep inside and all over your body. The human oral microbiome consists of both symbionts, microbes that we manage to live with and can even be said to need, and pathobionts, more opportunistic organisms that can lead to a state of disease if given the chance to proliferate unchecked. But the definition a symbiont versus a pathobiont is heavily perspective dependent. Keep that in mind for the moment.
When the relative population dynamics of an oral microbiome in symbiosis encounters “turbulence” it can be said that the resultant state is one of “dysbiosis”, a state of community disturbance. Dysbiosis might arise from a slew of confounding factors that predispose a shift in the composition and relative abundance of microbial communities. Insofar as the proportional makeup of dysbiotic communities strays from the snapshot of that same community makeup during health, it can be said to lie at the root of many systemic microbiome related infections. The switch is usually directed by certain important pathogens called the “keystone pathogens”, which, in a domino effect, have the ability to modulate the makeup of microbial communities once they take hold. One such persistent oral infection is periodontitis. I’ll be frank, when I was working at Noma, it’s not like we had health benefits, or even tons of cash. It took me finally quitting after my whole 6+ years there to go to the dentist for a regular checkup (save for the emergency root canal I got during Noma Mexico). My dentist asked if my gums sometimes bled when I brushed or flossed, and I said ya, but thought nothing of it. She checked my gum line, and let me know that some of my gum pockets were deep, and that I needed to get special picks and clean them super regularly if I wanted to avoid serious trouble. This was the early onset of periodontitis. Periodontitis is the constant inflammation of the gum line surrounding your teeth, and given enough time, it can lead to the gum line’s recession, a weakening of tooth’s root, and tooth loss. Keystone pathogens like Porphyromonas gingivalis can co-habitate alongside many species present within a healthy microbiome, often beneath levels of detection even when microbial analyses are performed using standard techniques. But given the right confluence of circumstances, such bacteria’s numbers can grow. Not in an explosion, but just enough to alter their ratio in their environment relative to other bacterial commensals. But what sort of circumstances? Well, poor oral hygiene, dietary habits, smoking, genetic difference, and dysfunction of the salivary glands, and sometimes, as one scientist put it, even just plain bad luck.
I won’t feign an intimate understanding of just how complex these interactions are. The papers I’m pulling some of this info from aren’t able to so either. Community interactions between individual microbes can be mind bogglingly complex. Approximately 500 to 700 species are estimated to reside in the oral cavity, of which half can be cultivated anaerobically in the lab through current microbiological techniques. However, the other half still remain unculturable in vitro, thus eluding our study of them in the lab. Scientists still don’t have a firm enough grasp on their environmental needs or behaviours to place them into a petri dish primed with agar and watch them grow, even if those very microbes are teeming in their own mouths. This might seem surprising, we sometimes think that all that science touches has long been catalogued, and all that’s left is to do is go through our findings with ever finer toothed combs, but in reality we’re still shrouded in ignorance about the living world (quite literally) right in front (or under?) our nose.
In the broadest strokes however, its by no means controversial to state that such diverse communities are built off delicate webs of interdependence. In the same way that a forest growing onto virgin ground after a forest fire or flood evolves over time, and never looks the same at any two points in time between the first sprouts of pyrophytes to take root, and the rich panoply of life to be found, sometimes exclusively, at every level of the forest between the floor and the canopy. Sure, its important to see the forest for the trees, but its also important to see all the environments nestled fractally within the forest, and within each individual tree. This past summer, I travelled to the Cayman Islands to make Palm Wine. I remember vividly being 20 m up in the canopy, peeling back a coconut frond to try to tap the tree, and discovering an arboreal ant colony buzzing about in the tree top.
Any bodily system functions the same way. For the sake of our own sanity or even understanding each other, we have no choice but to simplify discussions about what lives within us, and where, but to organisms 12 orders of magnitude smaller than we are, each one of us is a whole planet (you are, after all, only 8 orders of magnitude less voluminous than the earth itself). The environment of you is as variegated as the alps are from the ocean. And even within your mouth alone, you find pockets of difference as dissimilar to one another as the Sahara is from the everglades.
When you’re born, species of Streptococcus are usually the first pioneering microbes to plant their flag in your mouth. Streptococcus salivarius found mostly on the tongue dorsum and in saliva, Streptococcus mitis on the mucosal lining of the cheeks, and Streptococcus sanguinis on the gums. The growth and metabolism of these pioneer species change local environmental conditions such as local redox potential, pH, and availability of nutrients, factors which prime the environment for more fastidious organisms to grab a foothold after them. Over time, other microbial communities take over, Prevotella, Fusobacterium, Neisseria, Lactococcus and more and the total variety of genera blooms. By the time your adult teeth come in this continual succession of microbes is eventually replaced with a stable homeostasis of microbial communities referred to as the climax community, whereby different bacteria interact to establish an ecosystem where each community contributes in some form to the support of the others, and to the overall dynamic continuity of the environment that is your mouth.
Let’s examine just what that homeostasis really means. Like the improvised percussionists in the “STOMP” the metabolisms and actions of individual bacteria don’t ever seem to sound like music, but with of them interacting on the same stage, and wondrous harmonies begin to emerge out of the fugue. This music is homeostasis.
Let’s take a look at a fascinating subset of that homeostasis within your mouth, because as mentioned, as an environment, it is not a monolith. With the development of adult teeth, a new, lasting habitat is created, the gingival crevice, which is cleaned and nourished by a secretion your body produces called gingival crevicular fluid (GCF). Along with saliva, GCF is critical for the maintenance of the integrity of your gum line and contains antimicrobial peptides and immunoglobulins, but interestingly, it also contains a range of other active proteins and nutrients that support the resident microflora, influencing the ecology of the oral cavity. The secretion of gingival crevicular fluid physically flushes out the crevice, providing a stream of fluid pressure that defends against the microbial insult, but it also counterintuitively delivers novel nutrients, in the form of proteins and glycoproteins, for bacterial metabolism to the same area. These include iron rich molecules, like haemoglobin and transferrin. But unlike to dental cavities, many bacteria associated with periodontitis can’t metabolize carbohydrates for energy and are proteolytic too. It should be noted that as inflammation from periodontitis increases, your body produces more and more CGF in an attempt to flush out the irritant culprits, but simultaneously feeds them at the same time. A double-edged sword.
If you’ll forgive my aside, this is a highly interesting and recurrent theme that pops up again and again in host-microbe interactions. As I mentioned in regard to the yogurt bowl, there is a certain… inevitability to life making its way into any space capable of hosting it. Like an intrepid dandelion pushing out the side of a cracked concrete wall, microbial life acts in exactly the same way, if not more so. It would be a teleological misnomer to talk about your body as being “aware” of this fact and having taken actions over evolutionary time against it. But its not wrong to frame this constant encroaching as so strong selective pressure that our genomes had no choice but to malleably evolve both in spite and because of it. The gingival fluid contradictorily must flush microbes out of one your mouths most sensitive boundaries, and use chemical defences to deter their proliferation, but also provide certain microbes with the nutrient needed for their survival. Curiously, we cannot say whether the proteinous exudates found in this fluid are consumed opportunistically by the anaerobic bacteria that find their way into the gum line, or if we’ve evolved to nurture their presence. But perhaps the point is moot. Nature doesn’t operate in absolutes. In reality, the evolutionary history of such symbioses is most definitely a combination of these two angles. But within that reality lies a fascinating truth. No matter how you look at it, our genome has evolved to not just accommodate but actively support our microbiota. Their constant presence over generational time forced changes in our genome. And changes in our genome can be said to have dictated what species of bacteria were given a welcome invitation to call us home. The genetic, co-evolutionary feedback leads to a tenuous balance. CGF contains within it, promotional but also suppressive biological factors.
But note, the bacterial keystone pathogens that lead to oral disease are normal members of your hugely diverse oral microbiome. It is only when pathobiont populations relative to the other microbes in your mouth experience a tectonic shift that we recognize a swing from symbiosis to dysbiosis. It’s almost as if the members of a choir that were once signing in harmony decided to switch up their roles, leading some tenors to start singing in baritone, thus throwing off the luster of the hymn even if no one singer left the stage. But that analogy, while useful, isn’t perfect. A choir is made up of 4 voice types with 20–30 singers, your oral microbiome numbers hundreds of species, totalling tens of billions of individuals. That diversity is strength. Even if disrupted, between many species, there is metabolic redundancy that can see the same macroscopic effect of homeostasis arise from a slew of different starting points. The harmony of symbiosis is at once delicate but robust. It is a dynamic equilibrium. A complex of interactions that, even when constantly changing, converges upon the same result, nominally, that of a “healthy mouth”.
But that equilibrium is a tenuous one. The normal metabolisms of the very same microbes we’ve evolved to host will also eventually lead to the deterioration of their environment if not managed consistently. Poor oral hygiene is being one of biggest underlying factor of oral disease. You see, the microbes in your mouth aren’t just camping out in stasis. They’re alive, and constantly eating food and expelling waste. As detritus from your meal gets stuck in your teeth, your microbe feast, and produce lactic acid among other products as a function of their metabolism. If left alone, this acid accumulates and lowers the pH of your mouth to the point of being able to degrade your dental enamel. This creates cavities, which serve as new (often anaerobic) niches for the keystone pathogens of responsible for the aforementioned advanced oral diseases.
Dental carries are no laughing matter. Tooth decay can lead to sepsis and has been correlated to other ailments of the body ranging from Alzheimer’s to cardio-vascular disease and rheumatoid arthritis. But the carbohydrate-loving lactic acid bacteria that make up the bulk of our oral microflora are inviting into the house; we’ve even evolved biologically to make their stay as hospitable as possible. But why is that? The coevolutionary state of our oral microbiome is the END result of millions of years of microbe/mammalian interactions. Why have we not evolved to produce bacteriocins in our blood and release them to keep our mouths as sterile as our blood stream? Well two reasons. Sterility is about as real and attainable as Plato’s forms. Every gram of food we ingest brings about a million microbes into our bodies via our mouth. Thus we return to the notion of inevitability in these ecological frameworks. At the end of the day, if somethings going to live within you, better the devil you know. Their presence suppresses the levels of more harmful pathogens through colony resistance. Just by virtue of their being there, microbes like Streptococcus and Lactococcus, and other communalistic species take up physical space within your mouth, stealing real estate and resources from mare harmful species. This is to everyone’s benefit. Because should this dynamic equilibrium between species collapse, so too would their home. By inviting in the microbes whose presence we can tolerate and whose negative effects we can mediate, we stave off worser fates. We domesticated dogs and pay tax on their company that comes out of our food budget, and in turn they keep wild wolves at bay. Wolves that would eat both us and our food if they could. The freeloading burglar keeps the axe murderer out the house.
And the other reason… Earlier on, I mentioned that we’ve evolved alongside our microbes both evolutionarily and culturally. The fact that from a young age we’re taught the importance of dental health cannot be disregarded. Cultural evolution is as powerful a force as genetic factors in determining the fitness of organisms, and their microbial entourage, collectively, what we some like to call the holobionts, (the whole life). At the end of the day, post dinner, you might have as many as a billion microbes living on each tooth. The act of brushing knocks that down to a thousand. Brushing one’s teeth is by no means a modern or Western phenomenon either. Chew sticks made of Salvadora persica, aka the Toothbrush Tree, have been used for over 1000 years in Africa and Arabia. In India the twigs of tea trees, neem, and licorice are all used for the same purpose, for the antimicrobial agents they contain within their wood. The practice in the region dates back to at least ancient Babylonia, five and a half thousand years ago. This constant maintenance can never completely eliminate the microbes in your mouth. They bounce back with time. This is kind of the whole reasons why I’m spending so much time talking about dentistry — oral health when viewed from the perspective of microbial ecology is tantamount to forest ranging. You’re the Ranger Smith in Jellystone National Park, and for the good of the forest — the rich, dynamic and biologically diverse place that it is — well, you regularly have to go out with a gun and do your job.
The mouth is a microcosm. Health to a mouth becomes a type of exercise that melds culture and biology. As much as we might love the idea of quick-fix panaceas, if your doctor assesses your risk of non-communicable diseases and tells you to get more exercise to stave off what she perceives to be an inevitable heart attack, going to the gym once will not save you. She’s instructing you to create lasting behavioral change that consistently and persistently modifies the environment the cells of your body experience as their home. The same goes for the bacteria that call your body a home.
Let’s zoom waaaay out now, to look at the other half the equation, let’s return to the idea of convergence, and just how its possible that I, as an 8 year old kid, was able to recreate a similar product to traditional dairying societies that have been masterfully producing foods like yogurt continually, without interruption for thousands of years. Well, as spontaneously as microbes appear in your mouth, they also appear in your food. But that’s not a one way street. Boundaries are fuzzy things. And anything that can come in through a door can also use that door as an exit.
In one of the papers I found in my research for this talk, there was a graph of a phylogenetic tree identifying 118 cultivable species of bacteria found in a sample human oral microbiome. In combing through the taxa, I found no less than 38 bacterial species that are regularly employed in fermentation. From Lactococcus lactis in your Activa fruit cups, to the Streptococci performing malolactic fermentation, or Actinomyces species that are part of the foundational flora of Chinese Baiju, your body is a veritable vault of the microbes employed in food fermentation. The same lactic acid bacteria that my mother would have me brush out of my mouth each night (not that she ever employed microbiology to get me to wash up for bed) are also the ones humans the world over employ wittingly or unwittingly in the production of fermented food. Like the mythic stir sticks passed down from Grandmothers to their daughters, the tools we use for food can become totems for the microbial lineages that live around us, on us and in our food. My bright yellow plastic Ikea spoon that morning may have held less meaning, but it no less accomplished the task. Like an interplanetary spaceship, they transferred microbes from the environment of my mouth to a new world, in a bowl full of milk, sweetened with bits of Honey Nut O’s. This gets at a tenet of biology postulated my Bass Becking. That everything is everywhere, but the environment selects. All manners of microbes from my mouth ended up in that bowl, but the ones primed to thrive in milk and dine on lactose were the ones to blossom.
Without the accidental introduction of lactic acid bacteria into that bowl of milk, any number of wild microbes might has truly spoiled it not into a pleasantly sour and mildly sweet, thickened version of itself, but something pink and green and putrid. The benefit of the transformation is yogurt’s low pH, created by the microbes responsible for the fermentation. Yogurt is a form of preserved milk. Looking back through history, such a simple benison as longer shelf life (though there are plenty of strictly hedonistic reasons to enjoy fermented foods) served as enough of a push wherever humans lived, that we encoded the rituals responsible for their creation into our cultures, and preserved them until today. Those rituals have become our comfort foods, our special occasion foods and our traditions, no matter if you’re a second generation South Korean American enjoying kimchi for breakfast, or a Papua New Guinean native sipping on yawa at dusk.
One such traditional societies persist to today in Tibet. There, they milk yaks, not Canadian bred Holsteins. The yak is central to all aspects of life. Essential to all households, the domesticated yak provides a means of transforming the cold, rocky, high altitude land of the Tibetan Plateau, a region viewed as unproductive by the CCP, into farmable land. The animals graze on vegetation unsuitable for human consumption, transforming it into their very bodies. Powerful bodies that can be equipped with ploughs for ploughing the land, helping with the harvest and carrying heavy loads. The dung, when dried and mixed with straw provides fuel for fires. The yak offers up its soft white wool for warmth, in the form of blankets and garb, but also its long black hairs for utility, woven into rope and cloth for Nomad tents. At the end of its life, yak hide provides leather for making shoes, and saddle bags when travelling by horseback. Meanwhile, its meat proves sustenance; first dried by the sun in summer, and stored as part of a staple diet in winter. But to value a yak solely for its flesh is to waste a valuable and productive life to the peoples who live on the “roof of the world”. A live yak of reproductive age, can be milked throughout the summer but also through the winter, lending their milk to their herders who must share it with claves that wean for up to two years (in contrast, a factory farmed Angus heifer can be sent to slaughter at the same age or younger). Yaks give milk for drinking fresh, but also for making zho, a thick and sour yak milk yogurt, cultured with backslop that stretches back further than any Tibetan can remember. In the culture are some 50 different species of lactic acid bacteria and no less 9 different species of yeast. Genera like Lactococcus, Lactobacillus, Pseudomonas, and Streptococcus all show up in abundance, and wouldn’t you guess, they’re all regular members of the human microbiome too, not just the mouth either.
On Tibet’s border territory with China, zho is made of cow’s milk, with Tibetans describe as “relatively tasteless”. Zho, if not consumed immediately with brown sugar, rice, or atop boiled wild sweet potato, is most often churned in the tanned stomach of a lamb, to turn it into yak butter, which, if wrapped in yak leather, or rhododendron leaves, can last up to a year. Used not just for all the standard edible applications you could imagine a cheesy butter to fill, yak butter can fuel lamps, serve as an art supply, skin moisturizer and leather tanner. But it is most loved as Yak butter tea, sipped on 4 or 5 dozen times a day, consisting of hot tea, the butter, and a pinch of salt, it’s Tibet’s national drink (fuck your bulletproof coffee)
To Tibetans, their folk knowledge of what leads them to long lives and health is intrinsically tied to the practices of preservation that have allowed them to thrive to in some of the most rarified air on Earth. In my Encyclopedia of Fresh Fermented Milk Products, Zho is credited with being beneficial to the gastrointestinal tract, and long life. And I believe it. As far as health claims go, that’s pretty restrained. They’re far from the spurious and sometimes outlandish claims made by Westerners about cure-all superfoods that disproportionately and I quote “seem to benefit the individuals that sell them”. Take the extreme example of kombucha. It’s been purported to for treat AIDS, slow aging, anorexia nervosa, arthritis, atherosclerosis, cancer, constipation, and diabetes, help your digestion, rid your body of toxins, boost your energy, boost your immune system, help you lose weight, ward off high blood pressure and heart disease, and prevent cancer. PHEWPH. The problem is that all of these claims seem to come in the form of anecdotes from people who drink Kombucha, and have lived a life. They are not founded on research conducted in double blind, large cohort control trials. And this is why it’s sometimes so hard to separate the wheat from the chaff when it comes to fermentation. The people who want to believe in the benefits only decry its praises when a positive correlation is made and also, tend to speak the loudest. It is a statistical fact that there are individuals who succumbed to cancer last year who also drank kombucha. But you can’t credit kombucha for not doing something. Likewise, if you told your doctor you were going to forgo targeted chemotherapy and instead start drinking tea, they just might order a psychological assessment before releasing you.
But there are links to be made, we just have to be very sober about how we think about them. First, like brushing ones teeth to regularly rid the environment of you of the accumulation of bacteria and their biofilms in the form of plaque, the health benefits of fermented foods should equally be viewed as being meaningful when they turn into a regiment, like exercise. “I can’t remember the books I’ve read any more than the meals I’ve eaten, but either way, they have made me” A quote from an author, but funny that, if you reverse it, is equally attributable to the cook. As we’ve seen, you’re a dynamic environment yourself. What you’re made of is never fixed, but constantly shifting. If you regularly eat foods full of life that happen to be part of “a healthy forest”
In nature, every opportunity costs something not accomplished elsewhere, in some other environment. Biology as a series of mutually exclusive trade offs and compromises. And when you choose to consume ferments on a regular basis, you’re also omitting a whole slew of other foods that, if you live in a western country like me, are probably inert, highly processed and narrow in their dietary contribution. If you put Kimchi on your plate you leave mashed potatoes off. If you have water kefir as your drink, you aren’t drinking coke.
If you leave a bottle of Coca-Cola on the counter for a week nothing will grow in it, no microbe will take up camp. Under a microscope it will remain the same, (just flat) because there are enough preservatives, and a low enough pH that life just can’t thrive in its sugar medium. But if you take a head of cabbage, shred it and salt it, you thusly transform it. It transforms into an environment capable of fostering all the life already on its leaves, on your hands, and inside of your mouth and gut. When that happens, the croc that cabbage sits in transforms too, into a secondary gut — a secondary stomach — capable of (literally) outsourcing the act of digestion in advance of your consumption it, with the boon of also having preserved it.
It’s so utterly true that you are what you eat. It might seem like a grandmotherly platitude, but the conservation laws that govern physics, well, they demand it. So it follows that the more you eat of these foods, the more you are these foods. With a consistent enough habit of putting ferments on your plate, the environment inside of you and outside of you will begin to blur. The reciprocation, this mirroring of active, living ecologies create a buffer to shocks and disruptions. It’s like an well trained army that should it need to fight, also has capable and well trained reserves, but ALSO, has a well maintained supply chain able to support it with well-maintained infrastructure. Bit by bit, the negative aspects of living in the modern world begin to ebb away thanks to your that well trained standing army, what microbiologists call “colony resistance”.
This way of thinking about what fermentation does for you will invariably lead to a healthy and sober conclusion about the nature of healthy fermented foods in your diet. They are not one-shot panaceas. They’ aren’t fountains of youth or magical elixirs. With a sustained regimen, they’re the ecological means to consistently support the diverse range microbial consorts we’ve evolved alongside over hundreds of thousands of years to depend on for our well-being. That’s the point.
There was a funny quip in the article on kombucha I pulled up during my research, one of the articles that trawled through the list of spurious claims. One of the authors stated that even though they understood the health claims to be wildly far reaching, they also framed the habits of a kombucha loving nut in the terms of a cost benefit analysis. Say that someone believes that drinking kombucha is in fact incredibly good for them, even if we can’t prove all the correlates, even if the claims are bunk, is there really a downside to the ferment’s constant consumption when you consider the alternatives? The answer is no. It’s not the worst thing in the world to consume on a regular basis, and again, if you’re someone inclined to do so, just think about what you’re opting out of when you opt in to brewing and consuming your own fermented drinks.
There is no doubt that Tibetan yak herders experience long life when they drink it their fermented milk dozens of times a day, ingesting the microbes that live in those products, but also the substrates they thrive in as well. The more the pie chart of fermentation takes up in your diet, the more attuned your body becomes as an environment to the microbes within and without.
I’d just like to finish off this talk with a thought about crops and farmland. The places where all this food we’re indirectly talking about comes from at the end of the day. The cabbage for your kraut, the wheat for my Cheerios, the grapes for wine and on and on… Within the he relationship between crops, monoculture and biodynamic farming, what does what’s best for the pest teach us about the “health” of the farm?
Just pause to think about monocultures. Think about how intensively a farmer growing just one crop on a massive plot of land has to plow their field, to ensure that just one crop actually grows. Or the sheer amount of chemical inputs that need to be sprayed upon and pumped into the Earth to turn a 2000 acre farm growing a single variety of wheat into a profitable venture. What would that 2000 acre farm look like with no intervention? Well in a just a few years it would begin to revert into a prairie. A prairie filled with rabbits and weeds and dandelion and hemlock and all sorts of things that you normally find in the wild.
Now contrast the above arrangement we humans have constructed to keep nature’s equilibrium at bay with the realities of a biodynamic farm — one where a farmer’s required to host a diversity of crops on their field, and be both less committed and reliant on cash crops for their living.
Think about what those two fields look like from the point of view of the pests that would happily reimagine the purpose of those fields as their dining rooms. Flipping perspectives as I speak to symbionts and pathobiomes and pests and crops teaches us a lot about the webs of interaction we’re truly trying to get inside of. Let’s imagine sample plots from both fields from the point of view of, say, a nematode worm, a worm whose real good at munching upon the roots of grasses all while causing blights and crop failures.
Let’s situate you, dear microscopic worm, in an area roughly one square meter across. For you that may as well be a country — the distance you could reasonably expect to travel within your lifetime because you’re just so small. You can eat lots of different types of food beneath the earth, but you definitely have your favourites. In the first scenario, lucky for you that your favourite food comprises the roots of the only type of food on offer. One whose root system sees one plant connect directly to another, and another, and another, and another… It’s all that’s on the menu. As you, dear worm have your favourite dish prepared every night, you are your kin are going to explode in numbers thanks to these manufactured times of plenty.
But if the farmer responsible for your tiny plot of lands decides to break up their field and plant wheat in some patches, or clover in another, wildflowers in the hedgerows, and trees hither and tither, trees that then grow flowers to support pollinators and anthills maybe, and all manners of insects, some of which might like to eat you, dear nematode worm, well all of a sudden your life as a worm gets a whole lot harder. Your favourite meals still there, albeit in smaller quantities, but the correlation isn’t a linear one. As a worm, the diversity of primary producing species on its own brings to the table categorically different impediments to your survival beyond just the amount of your base resources.
What is true in the above scenario for the environment of a farm, follows for the environment of you if you choose to ingest foods support a diverse set of microbes. By farming yourself, yourself, you build up resistance and robustness against the collapse of a more fragile alternative system, where a narrow set of inputs, often stripped of the complex molecules required by many gut microbes, are consumed inert, with extreme regularity. Should you monoculture your gut, you’ll face the consequences of those actions. Should you treat your gut like a biodynamic field, you’ll reap the benefits of the resilience and redundancy afforded by biological diversity. From root to frond, from nose to tail, from mouth, to gut, to butt, it’s all connected.
So, in summary, what is the framework through which we can best understand the health benefits of fermented foods? Well, when the sustained consumption of living unpasteurized ferments, and a variety of high fiber foods become habitual, the concept of “health” transitions from a destination, or a goal, to a never-ending journey — something you continually have to manifest and enact, with intent. Granted, this is made easier by virtue of fermentation’s delicious nature, the better you get at it, the more you’ll want to eat of it, the best sort of positive feedback (no pun intended) loop. But nonetheless.
Like your dentist says after any visit after where she’s found a cavity, “Cut back on the sweets, and make sure to floss and brush consistently, NO GETTING LAZY. If you do, you’ll just make your next visit here harder on yourself.” I wish that from a young age, there was more emphasis placed on understanding that dental health is microbiotic management. That’s because your health over the course of your life, be it oral or corporeal, is utterly dependent on the health of the life inside of you.
