Top Quotes: “Gulp: Adventures on the Alimentary Canal” — Mary Roach

Austin Rose
21 min readJan 3, 2025

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Introduction

“The taboos have worked in my favor. The alimentary recesses hide a lode of unusual stories, mostly unmined. Authors have profiled the brain, the heart, the eyes, the skin, the penis and the female geography, even the hair,” but never the gut. The pie hole and the feed chute are mine.”

“I don’t recognize any of the components of what I’m experiencing. Why can’t I do this? Why is it so hard to find words for flavors and smells? For one thing, smell unlike our other senses, isn’t consciously processed. The input goes straight to the emotion and memory centers. Langstaff’s first impression of a scent or flavor may be a flash of color, an image, a sense of warm or cool, rather than a word. Smoking jackets in a glass of Noel, Christmas trees in a hoppy, resinous India pale ale.”

Verbal facility with smells and flavors doesn’t come naturally. As babies, we learn to talk by naming what we see. “Baby points to a lamp,” mother says, ‘Yes, a lamp,” says Johan Lundström, a biological psychologist with the Monell Chemical Senses Center in Philadelphia. “Baby smells an odor, mother says nothing.” All our lives, we communicate through visuals. No one, with a possible exception made for Sue Langstaff, would say, “Go left at the smell of simmering hotdogs.”

“In our society, it’s important to know colors,” Langstaff says over a rising happy-hour din. We need to know the difference between a green light and a red light. It’s not so important to know the difference between bitter and sour, skunky and yeasty, tarry and burnt. “Who cares. Theyre both terrible. Ew. But if you’re a brewer, it’s extremely important.” Brewers and vintners learn by exposure, gradually honing their focus and deepening their awareness. By sniffing and contrasting batches and ingredients, they learn to speak a language of flavor.”

Taste

““The United States is a dumping ground for bad olive oil,” Langstaff told me. It’s no secret among European manufacturers that Americans have no palate for olive oils. The Olive Center — a recent addition to the Robert Mondavi Institute for Wine and Food Science, on the campus of the University of California at Davis — aims to change that.

It starts with tastings.”

“Sensory analysts and panels help with product development. They keep the flavors of established products on track when a formula is altered — say, to lower the fat or salt content. They work with the market research staff. When focus groups of consumers prefer one version of, say, a ranch dressing over another (or over a competitor’s dressing), sensory evaluators may be brought in to figure out the salient attributes of the more popular item. The food scientists can then work backward from those attributes to tweak the formula.

Why use humans rather than lab equipment? Because the latter would yield dozens of chemical differences between a pair of products. Without a human evaluator, it’s impossible to assign sensory meaning to, them. Which of those dozens of differences in chemical makeup translates to a perceptible flavor shift, and which is below the threshold for human detection? Which ones, in short, make the difference in the consumer’s mouth and mind? “And you can’t ask the consumer,” says Langstaff. “You ask the consumer, Why does it taste better?’ They say, ‘Because I like it better.” The consumer’s flavor lexicon is tiny: yum and yuck.”

“In 2010, inventor George Eapen and snack-food giant Frito-Lay took the comparison beyond the realm of metaphor. They patented a system whereby snack-food bags could be printed with a bar code allowing consumers to retrieve and download a fifteen-second audio clip of a symphonic interlude, with the different instruments representing the various flavor components. Eapen, in his patent, used the example of a salsa-flavored corn chip. “A piano intro begins upon the customer’s perception of the cilantro flavoring…. The full band section occurs at approximately the time that the consumer perceives the tomatillo and lime flavors…. A second melody section corresponds to the sensation of the heat burn imparted by the Serrano chili.” U.S. Patent No. 7,942,311 includes sheet music for the salsa-flavored chip experience.”

Pet foods come in a variety of flavors because that’s what we humans like, and we assume our pets like what we like. We have that wrong. “For cats especially,” Moeller says, “change is often more difficult than monotony.

Nancy Rawson, seated across from me, is AFB’s director of basic research and an expert in animal taste and smell. She volunteers that cats are more or less “monoguesic,” meaning they stick to one food. Outdoor cats tend to be either mousers or birders, not both. But don’t worry, as most of the difference between Tuna Treat and Poultry Platter is in the name and the picture on the label. “They may have more fish meal in one and more poultry meal in another,” says Moeller, “but the flavors may or may not change.”

The extent to which Americans project their own food qualms and biases onto their pets has lately veered off into the absurd. Some of AFB’s clients have begun marketing 100 percent vegetarian kibble for cats. The cat is what’s called a true carnivore; its natural diet contains no plants.

Moeller tilts his head. A slight lift of the eyebrows. The cook says, “Whatever the client wants.””

To experience taste, the molecules of the tastant — the thing one is tasting — need to dissolve in liquid. Liquid flows into the microscopic canyons of the tongue’s papillae, coming into contact with the “buds” of taste receptor cells that cover them. That’s one reason to be grateful for saliva. Additionally, it explains the appeal of dunking one’s doughnuts. Taste is a sort of chemical touch. Taste cells are specialized skin cells. If you have hands for picking up foods and putting them into your mouth, it makes sense for taste cells to be on your tongue. But if, like flies, you don’t, it may be more expedient to have them on your feet. “They land on something and go, ‘Oooo, sugar!””

“The study animal of choice for taste researchers is the catfish, simply because it has so many receptors. They are all over its skin. “Catfish are basically swimming tongues,” says Rawson. It is a useful adaptation for a limbless creature that locates food by brushing up against it; many catfish species feed by scavenging debris on the bottom of rivers. I try to imagine what life would be like if humans tasted things by rubbing them on their skin. Hey, try this salted caramel gelato, it’s amazing. Rawson points out that a catfish may not consciously perceive anything when it tastes its food. The catfish neurological system may simply direct the muscles to eat. It seems odd to think of tasting without any perceptive experience, but you may be doing it right now. Humans have taste receptor cells in the gut, the voice box, the upper esophagus, but only the tongue’s receptors report to the brain. “Which is something to be thankful for,’ says Danielle Reed, Rawson’s former colleague at Monell. Otherwise you’d be tasting things like bile and pancreatic enzymes. (Intestinal taste receptors are thought to trigger hormonal responses to molecules, such as salt and sugar, and defensive reactions — vomit or diarrhea — to dangerous bitter items.)”

By adding strawberry or vanilla — aromas we associate with sweetness — it’s possible to fool people into thinking a food is sweeter than it really is.

Gone are the colored pet-food pieces of the early 1990s. “Because when it comes back up, then you have green and red dye all over your carpet,” says Rawson. “That was a huge duh.””

“Mexican dogs, unlike American dogs, enjoy a little heat. Rozin’s work suggests animals have cultural food preferences too. Rozin was not the first academic to feed ethnic cuisine to research animals. In “The Effect of a Native Mexican Diet on Learning and Reasoning in White Rats,” subjects were served chili con carne, boiled pinto beans, and black coffee. Their scores at maze-solving remained high, possibly because of an added impetus to find their way to a bathroom. In 1926, the Indian Research Fund Association compared rats who lived on chapatis and vegetables with rats fed a Western diet of tinned meat, white bread, jam, and tea. So repellent was the Western fare that the latter group preferred to eat their cage mates, three of them so completely that “little or nothing remained for post-mortem examination.”

“For Arctic nomads, eating organs has, historically, been a matter of survival. Even in summer, vegetation is sparse. Little beyond moss and lichen grows abundantly on the tundra. Organs are so vitamin-rich, and edible plants so scarce, that the former are classified, for purposes of Arctic health education, both as “meat” and as “fruits and vegetables.” One serving from the Fruits and Vegetables Group in Nirlungayuk’s materials is “1/2 cup berries or greens, or 60 to 90 grams of organ meats.” Nartok shows me an example of Arctic “greens”: cutout number 13, Caribou Stomach Contents. Moss and lichen are tough to digest, unless, like caribou, you have a multichambered stomach in which to ferment them. So the Inuit let the caribou have a go at it first. I thought of Pat Moeller and what he’d said about wild dogs and other predators eating the stomachs and stomach contents of their prey first. “And wouldn’t we all,” he’d said, “be better off.””

Until kids are around two, you can get them to try pretty much anything, and Rozin did. In one memorable study, he tallied the percentage of children aged sixteen to twenty-nine months who ate or tasted the following items presented to them on a plate: fish eggs (60 percent), dish soap (79 percent), cookies topped with ketchup (94 percent), a dead (sterilized) grasshopper (30 percent), and artfully coiled peanut butter scented with Limburger cheese and presented as “dog-doo” (55 percent). The lowest-ranked item, at 15 percent acceptance, was a human hair.

By the time children are ten years old, generally speaking, they’ve learned to eat like the people around them.”

“The phenomenon starts early. Breast milk and amniotic fluid carry the flavors of the mother’s foods, and studies consistently show that babies grow up to be more accepting of flavors they’ve sampled while in the womb and while breastfeeding. (Babies swallow several ounces of amniotic fluid a day.) Julie Mennella and Gary Beauchamp of the Monell Chemical Senses Center have done a great deal of work in this area, even recruiting sensory panelists to sniff amniotic fluid (withdrawn during amniocentesis) and breast milk from women who had and those who hadn’t swallowed a garlic oil capsule. Panelists agreed: the garlic-eaters’ samples smelled like garlic. The babies didn’t appear to mind. On the contrary, the Monell team wrote, “Infants. sucked more when the milk smelled like garlic.”)”

“I would wager that if you look hard enough, you will find a welcoming mouth for any safe source of nourishment, no matter how unpleasant it may strike you. “If we consider the wide range of foods eaten by all human groups on earth, one must .. question whether any edible material that provides nourishment with no ill effects can be considered inherently disgusting,” writes the food scientist Anthony Blake. “If presented at a sufficiently early age with positive reinforcement from the childcarer, it would become an accepted part of the diet.” As an example, Blake mentions a Sudanese condiment made from fermented cow urine and used as a flavor enhancer “very much in the way soy sauce is used in other parts of the world.”

The comparison was especially apt in the summer of 2005, when a small-scale Chinese operation was caught using human hair instead of soy to make cheap ersatz soy sauce. Our hair is as much as 14 percent L-cysteine, an amino acid commonly used to make meat flavorings and to elasticize dough in commercial baking.”

Digestion

“Fletcherism held a good deal of intuitive appeal. Fletcher believed — decided, really — that by chewing each mouthful of food until it liquefies, the eater could absorb more or less double the amount of vitamins and other nutrients. “Half the food commonly consumed is sufficient for man,” he stated in a letter in 1901. Not only was this economical — Fletcher estimated that the United States could save half a million dollars a day by Fletcherizing — it was healthier, or so he maintained. By delivering heaps of poorly chewed food to the intestine, Fletcher wrote, we overtax the gut and pollute the cells with the byproducts of “putrid bacterial decomposition.” While other feces-fearers of the day advocated enemas to speed food through the putrefaction zone, Fletcher advised delivering less material.

Practitioners of Fletcher’s hyperefficient chewing regimen, he wrote, should produce one-tenth the bodily waste considered normal in the health and hygiene texts of his day.”

At one chew per second, the Fletcherizing of a single bite of shallot would take more than ten minutes. Supper conversation presented a challenge.”

“One thing to be said in favor of thorough chewing is that it slows an eater down. This is helpful if that particular eater is trying to shed some weight. By the time his brain registers that his stomach is full, the plodding thirty-two-chews-per-bite eater will have packed in far less food than the five-chews-per-bite wolfer. But there’s thorough and there’s Fletcher. Chewing each bite, say, a hundred times, Faulks said, could have the opposite effect. It would lengthen the meal so radically that the stomach could have time to empty the earliest mouthfuls into the small intestine, while the last mouthfuls are still on the table. Thereby making room for more. Fletcherizers’ meals could conceivably be so interminable that by the time they finally cleared their plate and set down their napkin, they’d already be feeling peckish again.

Not to mention, the morning’s half gone. “Who has time for this?” was the reaction of Jaime Aranda-Michel, a gastroenterologist with the Mayo Foundation, when I called to ask him about Fletcherizing. “You’re going to spend all day just having breakfast. You will lose your job!””

Before doctors could ship patients’ bodily fluids off to labs for analysis, they sometimes relied on tongue and nose for diagnostic clues. Intensely sweet urine, for instance, indicates diabetes.”

Sugar contributes to tooth decay only indirectly. Like humans, bacteria are fond of it. “Bacteria get all crazy — party, party — they metabolize the sugar, break it down, and they release their metabolites, and these are acid” (though not as acid as cola or wine). In other words, sugar itself doesn’t cause cavities; it’s the acidic metabolites of the bacteria that feed on the sugar. As with acidic foods, saliva dilutes the acid and brings the mouth back to a neutral pH.”

The notion that food smells make your mouth water is, science says, erroneous. Science has said this over and over, most recently in 1991, at King’s College London. Ten subjects donned plastic odor-delivering face masks and nickel-sized Lashley cups. (The Lashley cup, a sort of glandular beret, fits on top of the parotid and collects its secretions.) Food odors wafted into the volunteers’ noses: vanilla, chocolate, peppermint, tomato, and beef. Only one smell, and in only one subject, caused a significant increase in salivation. Oddly, this subject was a vegetarian, and she was smelling beef. Upon questioning, the woman revealed that the smell had nauseated her. The salivation was the kind that precedes throwing up.”

“There was a 2010 hullaballoo over the New York City restaurateur who invited diners to try cheese made from his wife’s breast milk. So reliable is breast-milk consumption as a delimiter of intimate family that Islam recognizes a category called “breast milk son,” which confers an exemption to the rules on segregation of the sexes. A man can be alone with a woman if she’s immediate family or if she breast-fed him as a child. (Sisters sometimes breastfeed each other’s infants, thereby creating breast-milk relatives.) Milk is thicker than blood, or about the same consistency.

Saliva

““It is a known observation among the vulgar that the saliva is efficacious in cleansing foul wounds, and cicatrizing recent ones, thus dogs by licking their wounds … have them heal in a very short time,” wrote the eighteenth-century physician Herman Boerhaave. He was correct. Wounds that would take several weeks to heal on one’s skin disappear in a week inside the mouth. In a 2008 rodent study, animals that licked their wounds healed faster than those that could not (because their salivary glands had been disconnected — a wound, alas, that even saliva cannot heal). More than just disinfecting is going on. Rodent saliva contains nerve growth factor and skin growth factor.

Human saliva contains histatins, which speed wound closure independent of their antibacterial action. Dutch researchers watched it happen in the lab. They cultured skin cells, scratched them with a tiny sterile tip, soaked them in the saliva of six different people, and clocked how quickly the wounds healed, as compared to controls. Other components of saliva render viruses — including HIV, the virus that causes AIDS — noninfective in most cases. (Colds and flus aren’t spread by drinking from a sick person’s glass. They’re spread by touching it. One person’s finger leaves virus particles on the glass; the next person’s picks them up and transfers them to the respiratory tract via an eye-rub or nose-pick.)”

“Egyptian scholar Ezzat Attiya issued a fatwa, or religious opinion, extending breast-milk-son status to anyone a woman has “symbolically breastfed.” For convenience’s sake, drivers and deliverymen could, by drinking five glasses of a woman’s breast milk, be permitted to spend time alone with her. In the ensuing ruckus, another scholar insisted the man would have to drink directly from the woman’s breast. Which is crazier: that Saudi courts, in 2009, sentenced a woman to forty lashes and four months in prison for allowing a bread deliveryman inside her home, or the notion that she might have avoided punishment by letting him suckle from her breast? The woman was seventy-five, if that helps you with your answer.”

Chewing & Swallowing

“You often hear about the impressive power of the jaw muscles. In terms of pressure per single burst of activity, these are the strongest muscles we have. But it is not the jaw’s power to destroy that fascinates van der Bilt; it is its nuanced ability to protect. Think of a peanut between two molars, about to be crushed. At the precise millisecond the nut succumbs, the jaw muscles sense the yielding and reflexively let up. Without that reflex, the molars would continue to hurtle recklessly toward one another, now with no intact nut between. To keep your human jaw muscles from smashing your precious teeth, the only set you have, the body evolved an automated braking system faster and more sophisticated than anything on a Lexus. The jaw is ever vigilant. It knows its own strength. The faster and more recklessly you close your mouth, the less force the muscles are willing to apply — without your giving it a conscious thought.”

“A less lethal and more entertaining swallowing misstep is nasal regurgitation. Here the soft palate — home turf of the uvula, that queer little oral stalactite — fails to seal the opening to the nasal cavity. This leaves milk, say, or chewed peas in peril of being horked out the nostrils. Nasal regurgitation is more common with children, because they are often laughing while eating and because their swallowing mechanism isn’t fully developed: “Immature swallowing coordination” is the reason 90 percent of food-related choking deaths befall children under the age of five. Also contributing: immature dentition. Kids grow incisors before they have molars; for a brief span of time they can bite off pieces of food but cannot chew them. Round foods are particularly treacherous because they match the shape of the trachea. If, say, a grape goes down the wrong way, it blocks the tube so completely that no breath can be drawn around it. A child is better off inhaling a plastic barnyard animal or toy soldier, because air can be inhaled through its legs or around its rifle. Hotdogs, grapes, and round candies take the top three slots in a list of killer foods published in the July 2008 issue of the International Journal of Pediatric Otorhinolaryngology, itself a calamitous mouthful. Jennifer Long, a professor of head and neck surgery at the University of California, Los Angeles, went so far as to declare hotdogs a public health issue. A candy called Lychee Mini Fruity Gels has killed enough times for the U.S. Food and Drug Administration to have banned its import.

Every now and then a food comes along that is so difficult to orally process that even healthy adults without dysphagia have trouble getting it down. Sticky rice mochi, a traditional Japanese New Years food, kills about a dozen people every year — along with puffer fish and flaming cheese, the world’s riskiest menu items.”

When you bite into an apple, the flesh deforms, and at a certain moment the cell walls burst. And there is your crunch. (Ditto crispy snack foods, but here the bubbles are filled with air.) “This is why fresh fruit is crisp, and also why it is a little bit juicy,” says van Viet. His voice is reedy and high-pitched, with a musical cadence.

As a piece of produce begins to decay, the cell walls break down and water leaks out. Now nothing bursts. Your fruit is no longer crisp. It is mealy or limp or mushy. The same thing happens with a snack food degraded by moisture: cell walls dissolve, air leaks out.

The staler the chip, the quieter. For a food to make an audible noise when it breaks, there must be what’s called a brittle fracture — a sudden, high-speed crack. “Like this.” Van Vliet is drawing graphs again. As you bite down on it, energy builds and is stored. In a millisecond, the hip gives way and the stored energy is released, all at once. Crack is a superb onomatopoeia; the word sounds like the noise, and the noise is the fracture. (Crumbly foods, by contrast, break apart quietly because the energy isn’t released all at once.)”

Crispness and crunch appeal to us because they signal freshness. Old, rotting, mushy produce can make you ill. At the very least, it has lost much of its nutritional vim. So it makes sense that humans evolved a preference for crisp and crunchy foods. To a certain extent we eat with our ears. The sound made by biting off a piece of carrot — more so than its taste or smell — communicates freshness. René told me about an experiment in which subjects ate potato chips while a researcher digitally altered the sounds of their chewing. If they muted the crunch or masked the higher frequencies, people no longer sensed the crispness. “They rated the chips as old even though the texture had not changed.””

If you must spend time in a digestive organ, I recommend the penguin stomach. Penguins can shut down digestion by lowering the temperature inside their stomach to the point where the gastric juices are no longer active. The stomach becomes a kind of cooler to carry home the fish they’ve caught for their young. Penguins’ hunting grounds may be several days’ journey from the nest. Without this handy refrigerated mode, the swallowed fish would be completely digested by the time the adults get back — “like going shopping and eating everything you bought on the way home,” as marine biologist Terrie Williams put it.”

“Secor knew before he arrived that the dinner-kicking-its-way-out scenario was extremely unlikely. Pythons kill their prey before eating it.” “And there’s no way stuff can move once it’s inside there.” There was in fact a weak spot. Secor pointed to a printout of the photograph I’d brought with me when I visited his lab in late 2010. Two-thirds of the way down the python’s exterior is a patch of black (dead) tissue — a poorly healed wound from some earlier incident. The rupture of this wound, Secor thinks, was caused by an alligator, let’s call him alligator B, who attacked the python while he was digesting alligator A. The python broke open at the poorly healed wound, and A popped out. So it wasn’t, at the end of the day, a case of dinner exacting revenge from within. Just another dog-eat-dog day in the Everglades.”

“I challenge you to find a more innocuous sentence containing the words sperm, suction, swallow, and any homophone of seaman. And then call me up on the homophone and read it to me.”

“DePeters speculates that there’s another reason for the huge capacity of the rumen. Ruminants graze on the open plain, easily visible and vulnerable to predators. “So they’ll go out and graze and take in a lot, then go and hide somewhere to ruminate and digest.” The rumen is a built-in to-go box.

Health Issues

“The active ingredient in Beano is an enzyme that breaks down certain complex carbohydrates, called oligosaccharides, found in large quantities in beans and other legumes. You have this enzyme in your colon, courtesy of bacteria that live there. Because your small intestine can’t absorb these complex carbohydrates, they carry on into your colon, where bacteria and their enzymes break them down — and create a lot of hydrogen in the process. Translation: beans make people gassy. Adding Beano to chili while it’s still on the table preempts this.

“The older you get, the slacker the muscles of your colon become and the more easily the organ balloons. As Len gaily remarked, “We get flabbier all over, inside and out.” Sixty percent of Beano customers, he said, are over fifty-five. People with coronary artery disease whose doctors steer them away from fats and red meat are often advised to incorporate beans into their diet as a replacement protein. “Some of these people,” said Kligerman, “would come back to their doctors, going, I’ll take my chances on a second heart attack over all this gas.” Cardiologists in the fat-fearing 1980s handed out Beano sample bottles like Halloween candy.

The other food group that troubles the middle-aged gut is dairy. About 75 percent of Asians, African Americans, and Native Americans are deficient in lactase, an enzyme secreted in the small intestine that breaks down lactose, a sugar found in milk products. In Caucasians the rate is around 25 percent. Most can digest milk sugars while they’re young, but they begin to lose the ability as they age. “Once you’re beyond suckling age,” Kligerman pointed out, “there’s no biological reason for you to absorb lactose.” Were it not for the persistent hand of the dairy lobby — Got Marketing? — the notion of grown-ups drinking milk by the glass might seem as odd here as it does in much of the rest of the world.

Milk products follow the same biological plot line as beans. An ornery carbohydrate makes it to the colon intact because the small intestine couldn’t break it down into something absorbable. Colon bacteria go to town on it, spewing clouds of hydrogen in the process. Gastroenterologists can easily diagnose malabsorption of lactose (or gluten, for that matter). In the Bay Area, where I live, people prefer to self-diagnose. And misdiagnose. “Dairy sugar often travels with dairy fat, and big fat loads are hard on the gut,” says gastroenterologist Mike Jones. “People who claim lactose intolerance tend to also voice a belief that they’re gluten-intolerant. Usually with no evidence of either.””

When people, stereotypically women, hold in their gas, they absorb more of it into their bloodstream, “so it comes out in the breath.”

Nastiness

The stench is a warning: this item contains a lot of bacteria and could (depending on which bacteria they are) make you sick. The scariest, stinkiest cuisines are in countries where both food and refrigeration are scarce. Rural Sudanese eat fermented (that is, decomposing) caterpillar, frog, and, less proteinaceously, heifer urine. Yet one more reason tourism has been slow to catch on in the Sudan.

“OWING TO THE limited talents of the colon as an organ of absorption, perfectly good nutrients are daily discarded. The small intestine has time to absorb only so much before passing the goods along to the colon. Bacteria in the colon break down what they can, creating vitamins and other nutrients in the process, but because the colon isn’t as well set up to absorb the locally produced bounty, some of it is excreted.

This topic came up during a conversation with pet-food scientist Pat Moeller, of AFB International. Moeller had offered an explanation for the disconcerting canine habit of autocoprophagia. “If you think about it” — and, improbably, we were — “a dog that eats its stool, in some cases, may be getting missing nutrients” by running a meal through the small intestine twice.

In some neighborhoods of the animal kingdom, your own is a regular second course. For rodents and rabbits, in whom vitamins B and K are produced exclusively in the colon (by bacteria that live there), the self-manufactured pellet is a large, soft daily vitamin.”

The rats, Barnes found, ate 45 to 100 percent of what they’d excreted each day. If you prevent a rat from doing this, Barnes further noted, it will quickly become deficient in vitamins B5, B7, B12, and K, thiamine, riboflavin, and certain essential fatty acids. Four years later, B. K. Armstrong and A. Softly, scientists with the Department of Biochemistry and the Animal House at Royal Perth Hospital, showed that preventing rats from eating their first round of excreta severely stunted their growth. Over the course of a forty-day experiment, young rats thusly stymied gained just 20 percent of their starting body weight, while an unhindered control group gained 75 percent.”

The Gut

“Generally and unfortunately, aerobic strains that are easy to grow and keep alive in the oxygen environment of a lab are unlikely to be the beneficial ones. Though researchers don’t know exactly which bacteria are the desirables, they do know they’re likely to be anaerobic species that thrive only within the colon. You want the creatures that are dependent on a healthy you for their own survival, the ones whose evolutionary mission is aligned with your own — your microscopic partners in health.

I asked Khoruts what exactly is in the “probiotic” products seen in stores now. “Marketing,” he replied. Microbiologist Gregor Reid, director of the Canadian Research & Development Centre for Probiotics, seconds the sentiment. With one exception, the bacteria (if they even exist) in probiotics are aerobic; culturing, processing, and shipping bacteria in an oxygen-free environment is complicated and costly. Ninety-five percent of these products, Reid told me, “have never been tested in a human and should not be called probiotic.”

“Khoruts gave the example of the gorilla, a fellow ape held back by the energy demands of a less streamlined gut. Like the cow, the gorilla lives by fermenting vast quantities of crude vegetation. “He’s processing leaves all day. Just sitting and chewing, and cooking inside. There’s no room for great thoughts.””

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Austin Rose
Austin Rose

Written by Austin Rose

I read non-fiction and take copious notes. Currently traveling around the world for 5 years, follow my journey at https://peacejoyaustin.wordpress.com/blog/

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