Cooked: A Natural History of Transformation (69 page)

^*
There are no rules here, but
I more or less tried to honor the classic “flavor principles”: an Asian
mix of ginger, garlic, coriander, and star anise for the turnips and beets; Indian
spices like turmeric, cinnamon, and cardamom for the cauliflower and carrots;
garlic, dill, and peppercorns for the cucumbers and green tomatoes.

^*
Though you
can
inoculate it if you want to: Some old-school pickling recipes call for adding some
whey to the brine, a liquid teeming with lactobacilli; I tried it once, adding a
spoonful of the clear liquid from the top of a yogurt container, and it did seem to
speed the process. But what’s the rush?

^*
Biologists use the term
“microbiota” to refer to a community of microbes, and
“microbiome” to refer to the collective genome of those microbes.

^*
Robinson, Courtney J., et
al., “From Structure to Function.”

^*
This is equally true for the
somewhat different bacterial communities found in other locations on the body—the
mouth, the skin, the nasal passages, and the vagina. In the vagina, for example,
dozens of species of
Lactobacillus
ferment glycogen, a sugar secreted by
the vaginal lining. The lactic acid produced by these bacteria helps maintain a pH
low enough to protect the vagina against pathogens.

^*
Hehemann, Jan-Henrik, et al.,
“Transfer of Carbohydrate-Active Enzymes from Marine Bacteria to Japanese Gut
Microbiota,”
Nature
464 (2010): 908–12.

^*
Margulis theorized that both
photosynthesis and cellular metabolism in animals began when bacteria took up
residence in the evolutionary ancestors of plant and animal cells, contributing
their metabolic expertise; eventually these invaders became the chloroplasts in
plant cells and the mitochondria in the cells of animals.

^*
Turnbaugh, Peter J., et al.,
“An Obesity-Associated Gut Microbiome with Increased Capacity for Energy
Harvest,”
Nature
444 (2006): 1027–31; Turnbaugh, P. J., et al.,
“A Core Gut Microbiome in Obese and Lean Twins,”
Nature
457
(2009): 480–84; Turnbaugh, Peter J., et al., “The Human Microbiome
Project,”
Nature
449 (2007): 804–10.

^†
This particular probiotic is
found in some kinds of yogurt. (Bravo, J. A., et al., “Ingestion of
Lactobacillus Strain Regulates Emotional Behavior and Central GABA Receptor
Expression in a Mouse via the Vagus Nerve,”
Proceedings of the National
Academy of Sciences
108 No. 38 [2011]: 16050–55).

^*
It has long been recognized
that people with autism and schizophrenia often suffer from gastrointestinal
disorders, and some recent work suggests there may be anomalies in their microflora.
It’s important to remember that correlation is not causation, and if there is
causation, we don’t know which way it goes. But evidence is accumulating that
certain microbes in our bodies can affect our behavior and do so for their own
purposes.
Toxoplasma gondii,
a parasite found in more than one billion
people worldwide, has been shown to inspire neurotic self-destructive behavior in
rats. The protozoa’s reproductive cycle depends on infecting cats, which it
does by getting them to eat the rats and mice in whose brains the parasite commonly
resides. When the parasite infects a rat or mouse, it increases dopamine levels in
its host, inspiring it to wander around recklessly in a way more likely to attract
the attention of cats; the mice and rats also become attracted to the smell of cat
urine, an odor that, under normal circumstances, causes them to flee or freeze.
“Fatal feline attraction” is the name for this phenomenon. In people,
the presence of
Toxoplasma gondii
has been linked to schizophrenia,
obsessive compulsive disorder, poor attention and reaction times, and a greater
likelihood of car accidents. (House, Patrick K., et al., “Predator Cat Odors
Activate Sexual Arousal Pathways in Brains of
Toxoplasma gondii
-Infected
Rats,”
PLoS ONE
6 No. 8 (August 2011): e23277 and Benson, Alicia, et
al., “Gut Commensal Bacteria Direct a Protective Immune Response Against the
Human Pathogen
Toxoplasma Gondii
,”
Cell Host & Microbe
6
No. 2 [2009]: 187–96.)

^*
The PARSIFAL (Prevention of
Allergy–Risk Factors for Sensitization Related to Farming and Anthroposophic
Lifestyle) study, conducted with nearly fifteen thousand children in five European
countries between 2000 and 2002, compared rates of asthma, allergies, and eczema in
children attending Rudolf Steiner Waldorf schools, children living on farms, and
control groups. The children living on farms (where they were regularly exposed to
dirt, microorganisms, and livestock) and the children in Waldorf schools (who ate
more fermented vegetables and who received fewer antibiotics and fever-reducing
medications) had lower rates of allergic diseases. Douwes, J., et al., “Farm
Exposure in Utero May Protect Against Asthma,”
European Respiratory
Journal
32 (2008): 603–11; Ege, M. J., et al., “Prenatal Farm
Exposure Is Related to the Expression of Receptors of the Innate Immunity and to
Atopic Sensitization in School-Age Children,”
Journal of Allergy and
Clinical Immunology
117 (2006): 817–23. Alfvén, T., et al., “Allergic
Diseases and Atopic Sensitization in Children Related to Farming and Anthroposophic
Lifestyle—the PARSIFAL Study,”
Allergy
61 (2006): 414–21. Perkin,
Michael R., and David P. Strachan, “Which Aspects of the Farming Lifestyle
Explain the Inverse Association with Childhood Allergy?,”
Journal of
Allergy and Clinical Immunology
117 (2006): 1374–81. (Flöistrup, H., et
al., “Allergic Disease and Sensitization in Steiner School Children,”
Journal of Allergy and Clinical Immunology
117 [2006]: 59–66.)

^*
Blaser, Martin,.
“Antibiotic Overuse: Stop the Killing of Beneficial Bacteria,”
Nature
476 (2011): 393–94.

^†
Consider the saga of the
once-common stomach bacteria
Helicobacter pylor
i. Long considered the
pathogen responsible for causing peptic ulcers, the bacterium was routinely attacked
with antibiotics, and as a result has become rare—today, less than 10 percent of
American children test positive for
H. pylori
. Only recently have
researchers discovered it also plays a positive role in our health:
H.
pylori
helps regulate both stomach acid and ghrelin, one of the key
hormones involved in appetite. People who have been treated with antibiotics to
eradicate the bacterium gain weight, possibly because the
H. pylori
is not
acting to regulate their appetite. See Blaser, Martin J., “Who Are We?
Indigenous Microbes and the Ecology of Human Disease,”
EMBO Reports
7
No. 10 (2006): 956–60.

^*
Zivkovic, Angela M., J.
Bruce German, et al., “Human Milk Glycobiome and Its Impact on the Infant
Gastrointestinal Microbiota,”
Proceedings of the National Academy of
Sciences
107 No. suppl 1 (2011): 4653–58.

¹
Isolauri, E., et al.,
“Probiotics: A Role in the Treatment of Intestinal Infection and
Inflammation?,”
Gut 50
Suppl 3 (2002): iii54–iii59.

²
Leyer, Gregory J., et al.,
“Probiotic Effects on Cold and Influenza-like Symptom Incidence and Duration
in Children,”
Pediatrics
124 No. 2 (2009): e172–79.

³
Vrese, Michael de, and
Philippe R. Marteau, “Probiotics and Prebiotics: Effects on Diarrhea,”
Journal of Nutrition
137 No. 3 (2007): 803S–11s.

⁴
Quigley, E. M., “The
Efficacy of Probiotics in IBS,”
Journal of Clinical Gastroenterology
42 No. Suppl 2 (2008): S85–90.

⁵
Michail, Sonia, “The
Role of Probiotics in Allergic Diseases,”
Allergy, Asthma, and Clinical
Immunology: Official Journal of the Canadian Society of Allergy and Clinical
Immunology
5 No. 1 (2009): 5.

⁶
Pagnini, Cristiano, et al.,
“Probiotics Promote Gut Health Through Stimulation of Epithelial Innate
Immunity,”
Proceedings of the National Academy of Sciences
107 No. 1
(2010): 454–59.

⁷
Saikali, Joumana, et al.,
“Fermented Milks, Probiotic Cultures, and Colon Cancer,”
Nutrition
and Cancer
49 No. 1 (2004): 14–24.

⁸
Messaoudi, Michaël, et al.,
“Beneficial Psychological Effects of a Probiotic Formulation
(
Lactobacillus helveticus
R0052 and
Bifidobacterium longum
R0175) in Healthy Human Volunteers,”
Gut Microbes
2 No. 4 (2011):
256–61.

⁹
Falagas, M. E., et al.,
“Probiotics for the Treatment of Women with Bacterial Vaginosis,”
Clinical Microbiology and Infection
13 No. 7 (2007): 657–64.

¹⁰
Brashears, M. M., et al.,
“Prevalence of
Escherichia Coli
O157:H7 and Performance by Beef
Feedlot Cattle Given Lactobacillus Direct-Fed Microbials,”
Journal of Food
Protection
66 No. 5 (2003): 748–54.

¹¹
Coillie, E. Van, et al.,
“Identification of Lactobacilli Isolated from the Cloaca and Vagina of Laying
Hens and Characterization for Potential Use as Probiotics to Control
Salmonella
Enteritidis,
”
Journal of Applied Microbiology
102 No. 4
(2007): 1095–106.

¹²
Corridoni, Daniele, et al.,
“Probiotic Bacteria Regulate Intestinal Epithelial Permeability in
Experimental Ileitis by a TNF-Dependent Mechanism,”
PloS One
7 No. 7
(2012): e42067.

^*
Smillie, Chris S., et al.,
“Ecology Drives a Global Network of Gene Exchange Connecting the Human
Microbiome,”
Nature
480 (2011): 241–44. Arias, Maria Cecilia, et al.,
“Eukaryote to Gut Bacteria Transfer of a Glycoside Hydrolase Gene Essential
for Starch Breakdown in Plants,”
Mobile Genetic Elements
2 No. 2
(2012): 81–87.

^†
And possibly for fermenting
your own vegetables at home, according to the CDC’s Kimmons: “Ideally,
you want to grow your own bacteria at home, since [these local strains] will best
reflect the world you live in.”

^*
Perkin and Strachan,
“Which Aspects of the Farming Lifestyle.”

^*
There are additional reasons
that may explain why people have become more vulnerable to pathogens over time: The
population is older; also, a substantial number of people have had their immune
systems compromised by chemotherapy and immune-suppressant drugs.

^*
Many cheese makers today use
“vegetable rennets”—chymosin produced by a genetically engineered
bacterium, mold, or a yeast.

^*
When the weather is cold,
another cheese maker told me, calves need more energy to keep themselves warm, so on
those days the proportion of fat in their mother’s milk increases.

^*
Perhaps this explains why so
many of the foods thought to best express
terroir—
such as wine and
cheese—are products of fermentation.

^*
See the footnote on
page 325
describing the process of
fermentation in the human vagina.

^*
Under current regulations,
only raw-milk cheeses that have been aged a minimum of sixty days may be sold in the
United States, and you would not want to eat a Camembert quite that old—it would
presumably have liquefied by then and begun to stink beyond approach. The theory
behind this rule is that the aging process should render the cheese safer, but it
now appears there is little scientific basis for this belief.

^*
The exception that proves the
rule is tears, which only humans produce, and which do not disgust.

^†
Of course, there is also an
adaptive value in being repulsed by putrefying matter, corpses, and feces: These
things often harbor pathogens.

^*
When I tried to revisit
Stillwaggon’s Web site in August 2012, the link no longer worked.

^*
“Jesus saith unto them,
Fill the waterpots with water. And they filled them up to the brim. And he saith
unto them, Draw out now, and bear unto the governor of the feast. And they bare
[it].When the ruler of the feast had tasted the water that was made wine, and knew
not whence it was: (but the servants which drew the water knew) the governor of the
feast called the bridegroom, And saith unto him, Every man at the beginning doth set
forth good wine; and when men have well drunk, then that which is worse: [but] thou
hast kept the good wine until now.

   “This beginning of miracles
did Jesus in Cana of Galilee, and manifested forth his glory; and his disciples
believed on him.” (John 2:7–11)

^*
One species of fruit
fly—
Drosophila melanogaster—
consumes alcohol as a way to medicate
itself; the alcohol poisons a tiny parasitic wasp in its gut that otherwise would
kill the fly. The alcohol kills the wasp by causing its internal organs to shoot out
of its anus. Milan, Neil F., et al., “Alcohol Consumption as Self-Medication
Against Blood-Borne Parasites in the Fruit Fly,”
Current Biology
22
No. 6 (2012): 488–93.