by Maria Reidelbach
By now, you may have heard the shocking scientific findings that 90 percent of the cells that we think of as our body, are actually, ick, germs! Trillions of microbes live on our skin, in our mouths and throughout our bodies, especially in our digestive tract. Cumulatively our “microbiome” weighs between two and six pounds.
|A friendly microbe.|
These microbes are not dangerous, in fact, it turns out we can’t be healthy without them. Scientists are even beginning to think of them as another organ. These tiny critters help us in many ways: metabolizing food into vitamins, training and tuning our immune system to protect against allergies and asthma, regulating our metabolism, and repelling harmful bacteria. This begins even in the womb, thought to be sterile until recently. Babies receive an additional anointment of helpful bacteria as they slide down mom’s birth canal, and vaginal birth babies tend to be healthier than those born by C-sections. Kids who are regularly exposed to farm animals and their dung, with resident bacteria, seldom have allergies or eczema. A change in gut biota can have an astounding effect on health, for example, bacteria transplanted from one body to another can cause the fat to become lean and vice versa, and a bacterial transplant is the only known cure for a common, but deadly infection caused by Clostridium difficile.
There are hundreds of studies in the works—understanding the microbiome promises to be one of the most important breakthroughs in biology ever. Scientists now know that we each have a unique microbiome, and that our bacterial populations vary based on our diets, our location, even time of day. Those who live in the same house (including pets) have a greater proportion of shared biota. Forensic scientists are discovering that we all leave behind traces of biota that are more unique than fingerprints (which, despite their historic use as evidence, are actually not). Even cadavers have been studied, and forensic scientists can now determine time of death with much greater accuracy, based on how the microbiome evolves after the host dies.
What’s also getting pretty clear is that there’s a big connection between what goes on in our belly and what goes on in our brain. How it all happens is pretty complicated, but fascinating. As the microbes metabolize nutrients, they secrete a huge number of chemicals, among them are the same substances that regulate mood. The best known neurotransmitters are dopamine and serotonin, substances that are used in antidepressants, pain-killing and recreational drugs. These and others travel via the vagal nerve network that connects the gut to the brain and also circulate in our blood. Biota in the gut also train immune cells that travel to the brain.
Scientists are seeing how all this molecular activity has a direct effect on our mental state and moods, particularly anxiety, depression, and even autism. Even though biologists are notorious for an unwillingness to concede that animals have emotions, they use mice to study them. When mice exhibiting anxiety- and depression-like behaviors are given a biota transplant, they become spunkier and more curious. Autistic mice who receive transplants of specific types of biota have responded markedly. There are many human studies are in the works, the few that have been completed are very promising. One landmark study in the journal Gastroenterology showed significant differences in anxiety levels between groups who ate yogurt with live bacteria twice a day for a couple of weeks, and those who ate pasteurized yogurt.
Because the mental effects of a healthy microbiome observed so far are very positive—inducing calm, happiness, and sociability—some scientists even go so far as to suggest that the biota evolved encourage this because through human interaction is the way they find new hosts!
Of course, even though all of this science is in its infancy, there are multitudes of supplement companies that are marketing probiotics claiming to cure almost anything. It’s important to know that probiotics are not regulated at all, so there is no way to know that you’re getting what’s on the label, let alone whether it will actually work if it is.
However, the good news is it’s surprisingly easy to cultivate your inner garden—yet another reason that it’s great to be a yardavore! First, be lazy! Ditch all those antimicrobial products and don’t be such a clean freak. Eat plenty of delicious cultured foods like traditional lacto-fermented pickles, sauerkraut, and yogurt (make sure they all have live bacteria). Eat whole foods and avoid processed foods. Studies show that a typical American diet with refined sugar, fat, and starches is like poison to a healthy microbiome. Avoid taking antibiotics whenever possible. Get outdoors, play in the dirt, regularly visit farms with livestock—even family dogs are shown to bring a huge diversity of bacteria. Sounds like a great life to me!
More info: humanfoodproject.com (you can participate in a study and get your own microbiome sequenced)
The Real Deal Sauerkraut (adapted from the Stick to Local Farms Cookbook)
1 large, firm, green or red cabbage, about 5 pounds
3 tbsp sea salt or 1 1/2 oz kosher salt (not iodized)
1 tsp caraway seeds (optional)
Shred the cabbage after removing the core. Put into a bowl and work the salt into the cabbage with your fingers until juicy. Pack into a non-reactive container, like a glass jar or ceramic crock. Add juice; if there’s not enough to cover the cabbage, top it up with a brine made from 1 cup filtered water and 1 tablespoon of sea salt.
Place a weight, like a small plate, over the floating cabbage shreds to keep them submerged (important—you want the brine to provide an anaerobic seal). Cover loosely with a clean dish towel and ferment at room temperature. Skim any floating bubbles or other matter. After about a week, begin to taste the sauerkraut every day until it’s to your liking. Remove the weight, cover the jar and refrigerate. Your kraut will smell weird before it smells tasty, this is part of the procession of fermentation. Occasionally the kraut will turn permanently slimy or smelly. It’s not dangerous, but it’s been colonized by the wrong bacteria; just throw it out and start over. The sauerkraut will keep in the refrigerator for up to 6 weeks.
Maria Reidelbach is an author, artist and local food activist living, working and eating in Accord, NY.