The Essential Book of Fermentation (6 page)

Your digestive system requires enzymes to properly break down your food and make full use of it. Enzymes are catalysts and allow for the full utilization of the nutrients in food. They are destroyed by heat hotter than 120 to 130ºF—especially the heat of pasteurization. If you eat a cooked potato that has had its enzymes destroyed in the cooking, your body rushes white blood cells to your intestines. These cells contain digestive enzymes that set to work deconstructing the potato. However, if you eat just a small amount of raw potato, that you might grate into a salad, for instance, the enzymes will be intact and your immune system won’t have to rush white blood cells to your intestine. But who wants to eat raw potato? The answer is to eat fermented foods, because most are not cooked and are full of digestive enzymes. So instead of the body’s having to rush white blood cells to your intestines to digest the cooked potato, your intestinal flora chips right in and helps with the deconstruction. Researchers have found that as we age, the supply of digestive enzymes produced by the body diminishes. Fermented foods keep us fully supplied.

We’ve seen that vitamin C in fermenting cabbage is more available to the body than the vitamin in raw cabbage. But this good result doesn’t stop with vitamin C. Fermented dairy products increase the level of folic acid, so critical in the healthy development of the fetus. Kefir in particular increases the level of riboflavin and biotin, two B vitamins, depending on the strains of bacteria present.

Finally, fermenting our foods makes them taste better, or at least more complex and intense. Many people feel that wine tastes better than grape juice, bread tastes better than flour, cheese tastes better than plain milk, and sauerkraut tastes better than raw cabbage, to name just a few examples. Our taste buds have developed over the millennia to guide us toward foods that are good for us. Newborns like a sweet taste because the mother’s milk that is their lifeline tastes sweet. When we were hunter-gatherers—through 99 percent of our species’ time on earth—salt, sugar, and fat were in short supply, and so we crave those tastes. That gets us into trouble today, when foods rich in salt, sugar, and fat—doughnuts, pizza, ice cream—are readily available. Now we need to exhibit restraint when it comes to these tastes. But you know what? Fermenting vegetables, milk, and other foods twists their flavor profile to satisfy these primordial cravings, even if the foods are not rich in salt, sugar, and fat. For example, grape juice tastes sweet because when grapes are ripe, about 25 percent of their weight is grape sugar. Yeast ferments that sugar into about half that weight in alcohol, which doesn’t taste sweet. And yet a well-made, rich red wine, like a Napa Valley Cabernet Sauvignon, strikes many people as sweet, even though there’s very little sugar in it. What they are tasting is the intense fruitiness of the wine, which only makes it seem sweet.

A Personal Health Story

Over a hundred years ago, Elie Metchnikoff, a Russian biologist, zoologist, and protozoologist who’s best remembered today for his pioneering research into the immune system, received the Nobel Prize in Medicine. Among his many lines of fertile inquiry, he found that kefir activates the flow of saliva, most likely due to its lactic acid content and its slight amount of carbonation. He also found that kefir stimulates peristalsis and digestive juices in the intestinal tract.

His work was strictly scientific, but I would like to add a personal anecdotal note about the effect of drinking kefir daily on the intestinal tract and the eliminative function. I would, if I could, recount my experience delicately, but perhaps it’s best told plainly, since we all share the same bodily functions—and, sometimes, dysfunctions.

I noticed, as I aged, that the strength of peristalsis—the squeezing function of the colon in moving feces toward elimination—began to taper off. More and more, I had to bear down to achieve a positive bowel movement. This bearing down by contracting the stomach muscles is dangerous. One can pop a blood vessel doing that. And it often resulted in bothersome hemorrhoids that at least itched when they weren’t positively painful. Not only that, but the more I used my stomach muscles to help peristalsis, the weaker peristalsis seemed to get and the harder I had to push, making the problem worse.

I had no idea that drinking kefir would help with this problem. I was surprised by the results of drinking my daily morning glass of kefir, for within a week, my bowel movements were larger and the new bulk stimulated my colon to regain its peristaltic oomph. Within a few weeks I could relax and let nature take its course; that is, let the body pursue elimination naturally and easily, without pushing. I would say the stool bulk increased from 30 to 50 percent after I started drinking kefir. The bacteria and yeast were obviously proliferating like crazy in my intestines, and it was all to the good.

Often there would be a second productive bowel movement later in the morning, with the same positive results. Hemorrhoids were gone. I felt clean and healthy inside and out. Finding kefir has made a significant difference in the quality of my personal hygiene. Sorry if it’s an indelicate subject, but I thought you’d like to know, because you might find the same benefits from a daily glass of delicious kefir.

Some mornings I drink the kefir plain—it’s that good. But I also went to the market and bought a bag of frozen wild Maine blueberries, a bag of frozen dark sweet organic cherries, and a bag of frozen organic black raspberries. At home, I dumped them into a pot, set the pot on low heat with the lid on, and when the fruit was thawed and hot, mashed it with a potato masher. Then I lined a colander with three layers of cheesecloth, sat it on a bowl, and poured the contents of the pot into the cheesecloth. I worked the solids back and forth with a tablespoon until all the juice had collected in the bowl. Then I stirred in two tablespoons of Sucanat and the juice of a lemon, poured this mixture into an empty quart jar, and put it in the fridge. On some mornings when I want a treat, I pour a few tablespoons of this syrupy, fruity mix into my glass of kefir and stir it up. Delicious!

This last delightful information is to make up for all the bathroom talk that preceded it.

CHAPTER 2

Fermented Foods as Probiotics

The long lives of some Bulgarian and Russian citizens have been credited to their consumption of large amounts of yogurt. The key organism that turned milk into yogurt was later identified as
Lactobacillus acidophilus.
This by-now-familiar organism (see the milk department of any supermarket), at work in yogurt, cheese, and other dairy products, enzymatically changes lactose—milk sugar—into lactic acid. It may do this in a dish of ripening yogurt or in the human intestine. There are some major benefits of this change. The lactobacilli attach themselves temporarily to sites all over the digestive tract, reducing the places where disease-causing germs can gain a foothold. They help the existing intestinal microbes absorb and metabolize the lion’s share of nutrients, making them unavailable to pathogens. They produce lactic and acetic acids, creating an acid environment unsuitable for harmful organisms, which prefer conditions near pH neutral. They turn lactose into lactic acid, reducing the discomfort of those who are lactose intolerant. Research has documented the ability of lactic acid–producing bacteria to inhibit
Escherichia coli,
Salmonella typhimurium, Staphylococcus aureus,
and
Clostridium perfringens
—all disease-causing pathogens. Studies have shown that these activities also stimulate the immune system.

In fact, recent scientific work in Brazil shows that our diverse intestinal microbiome is responsible for developing immune system responses that lead to inflammation and pain; that is, they help our immune systems acquire the ability to cause swelling and pain. This ability protects us, claims Arthur Ouwehand, a microbiologist at the University of Turku in Finland. He points out that pain and swelling are the body’s correct responses to a wound or infection. They signal the brain that something is wrong and that the immune system is working on the problem. The pain makes the person treat the injured area more carefully. The Brazilian studies were led by Mauro Teixeira, an immunologist who found that the presence of a healthy gut biome stimulated the immune systems of mice, producing larger numbers and more active white blood cells, among other benefits. The results imply that the right mix of diverse microorganisms in the gut could relieve pain in people with inflammatory diseases such as Crohn’s disease and eczema by healing the damaged gut, but such therapies are far from certain at this stage, Teixeira says. Still, his research “shows how profound an effect microbes have on your immune system and your entire health,” Ouwehand says.

That’s not all. Lactic acid bacteria produce bacteriocins. Bacteriocins can be likened to natural antibiotics that clear an area of competition, allowing the lactobacilli, in this case, to have the territory to themselves. They are attack proteins produced by many kinds of bacteria, not only lactobacilli. Most have a very broad operating range and remain active even after being frozen or boiled. They work by dissolving a hole in the cell wall of the competing bacteria, causing the cell contents to leak out and the cell to die. Because bacteriocins are a naturally occurring protein, they are assimilated back into the host after they finish their task.

If you think of yourself as a bacterium, and know that everywhere you want to get a toehold is already crammed with your competition, you can see why nature has given you the ability to spread your surroundings with a bacteriocide. It gives you a chance. The most thoroughly studied bacteriocin is nisin, produced by our friends so intimately involved in fermentation, the lactobacilli. It’s an approved food additive in the European Union and is used as a preservative in many kinds of cheese. Nisin is produced from the two main lactic acid–producing bacteria and protects cheddar, Colby, Monterey Jack, cottage cheese, brick, Limburger, Muenster, Swiss, Emmental, Gouda, Edam, Brie, Camembert, blue, Gorgonzola, Stilton, feta, Manchego, chèvre, and many others. It works like any other allelopathic bacteriocin: preventing other microbes from getting established.

German researchers are now investigating the possibility of using bacteriocins as a substitute for antibiotics to eliminate resistance caused by the overuse of antibiotics in humans and animals. Research has revealed that antibiotics actually
increase
the colonization of an intestinal tract by disease-causing salmonella bacteria, whereas the bacteriocins produced by lactic acid bacteria inhibit or eliminate it. Well, how can that be? Why would antibiotics increase the colonization of the intestinal tract by salmonella?

Organic gardeners and farmers know the answer. After a field is sterilized with chemicals that destroy most of its life forms, the first organisms to recolonize the field will be opportunistic weeds and plant-eating pestiferous insects that eat those weeds. The first plants back will certainly not be climax ecosystem plants that take many generations to appear as the ecosystem becomes diverse and stable. And the only insects that can thrive in a disturbed field recolonized by opportunistic weeds are insects that can eat those weeds. Only after the plant-eating insects become dominant will the good guys—the insect-eating insects—return. Evidently, the same idea holds true for an intestine cleansed of bacteria by an antibiotic. The first organisms back in may not be the good guys, unless steps are taken to make sure the first organisms back in are members of a healthy intestinal floral ecosystem. And that means seeding your sterilized intestines with microbe-rich fermented foods.

Fermented foods stimulate the body’s production of acetylcholine, a neurotransmitter that helps nerve impulses fire through their neurons. What this means is that functions like bowel peristalsis—the movement of feces through the bowel—are aided by acetylcholine, and this can improve regularity and curb constipation. It also helps the stomach, pancreas, and gallbladder produce their digestive juices and enzymes, which can greatly aid digestion.

The fact that fermented foods are predigested by bacteria lightens the load on the pancreas as it produces insulin that metabolizes carbohydrates. Carbohydrates in fermented foods are already broken down to an extent by the action of lactobacilli. People with diabetes, whose pancreases aren’t producing enough insulin, may benefit from consumption of ferments.

Fermented foods destroy and inhibit pathogenic bacteria. These foods protect us from harmful bacteria in many ways, by herding pathogens into colonies that are then isolated, by flooding the intestines with beneficial bacteria so there’s little room for pathogens to break out, by creating an acid environment that pathogens don’t like, by producing bacteriocins that control and inhibit disease-causing germs, and by other ways still not understood.

Dr. David Williams, a chiropractor and authority on natural healing techniques, says that the idea of using beneficial microbes to control pathogenic microbes is just catching on, “although it’s still baffling to me why conventional medicine hasn’t been able to grasp or accept this concept. Obviously, pharmaceutical companies stand to make a lot more money selling antibiotics and other medications than by recommending a daily dose of fermented cabbage.” Here’s another example of the correspondence between conventional medicine and conventional farming. Let’s repeat the last statement, substituting a few words: The idea of using beneficial insects to control plant-eating pests is just catching on, although it’s still baffling to me why conventional agriculture hasn’t been able to grasp or accept this concept. Obviously, agricultural chemical companies stand to make a lot more money selling pesticides and other agrichemicals than by recommending the annual release of ladybugs.