Sphincters, sensor cells, consciousness, and electrode-up-the-butt quiz shows. My flatmate was probably not expecting all that in answer to his casual question about pooping, nor did the group of rather prim female business studies students who had meanwhile gathered in the kitchen for his birthday party. Still, the evening turned out to be fun, and it made me realize that a lot of people are actually interested in the gut. Some interesting new questions were raised at the birthday party. Is it true that we don’t sit on the toilet properly? How can we burp more easily? Why can we get energy from steaks, apples, or fried potatoes, for example, but cars are much more restricted in their fuel options? Why do we have an appendix? Why are feces always the same color?
My flatmates have learned to recognize the familiar look on my face when I rush into the kitchen, bursting to tell them my latest gut anecdote—like the one about the tiny squat toilets and luminous poop.
Are You Sitting Properly?
IT’S A GOOD idea to question your own habits from time to time. Are you really taking the shortest and most interesting route to the bus stop? Is that comb-over to hide your increasing bald patch elegant and chic? Or, indeed, are you sitting properly when you go to the toilet?
There will not always be a clear, unambiguous answer to every question, but a little experimentation can sometimes open up whole new vistas. That is probably what was going through the mind of Dov Sikirov when the Israeli doctor asked twenty-eight test subjects to do their daily business in three alternative positions: enthroned on a normal toilet; half-sitting, half-squatting on an unusually low toilet; and squatting with no seat beneath them at all. He recorded the time they took in each position and asked the volunteers to assess the degree of straining their bowel movements had required. The results were clear. In a squatting position, the subjects took an average of 50 seconds and reported a feeling of full, satisfactory bowel emptying. The average time when seated was 130 seconds and the resulting feeling was deemed to be not quite so satisfactory.
Why the difference? The closure mechanism of our gut is designed in such a way that it cannot open the hatch completely when we are seated. There is a muscle that encircles the gut like a lasso when we are sitting or, indeed, standing, and it pulls the gut in one direction, creating a kink in the tube. This mechanism is a kind of extra insurance policy, in addition to our old friends, the sphincters. Some people will be familiar with this kinky closing mechanism from their garden hose. You ask your sister to check why there’s no water coming out of the hose. When she peers down the end, you quickly unbend the kink, and it’s just a few minutes until your parents ground you for a week.
But back to our kinky rectal closure mechanism: it means our feces hit a corner. Just like a car on the highway, turning a corner means our feces have to put on the brakes. So, when we are sitting or standing, our sphincters have to expend much less energy keeping everything in. If the lasso muscle relaxes, the kink straightens, the road ahead is straight, and the feces are free to step on the gas.
Squatting has been the natural defecation position for humans since time immemorial. The modern sitting toilet has existed only since indoor sanitation became common in the late eighteenth century. But such “cavemen did it that way” arguments are often met with disdain by the medical profession. Who says that squatting helps the muscle relax better and straightens the feces highway? Japanese researchers fed volunteers luminous substances and X-rayed them while they were doing their business in various positions. They found out two interesting things. First, squatting does indeed lead to a nice, straight intestinal tract, allowing for a direct, easy exit. Second, some people are nice enough to let researchers feed them luminous substances and X-ray them while they have a bowel movement, all in the name of science. Both findings are pretty impressive, I think.
Hemorrhoids, digestive diseases like diverticulitis, and even constipation are common only in countries where people generally sit on some kind of chair to pass their stool. This is due not to lack of tissue strength, especially in young people, but to the fact that there is too much pressure on the end of the gut. Some people tend to tense up all their abdominal muscles when they are stressed. Often, they don’t even realize they are doing it. Hemorrhoids prefer to avoid internal pressure like that by dangling loosely out of the anus. Diverticula are small light-bulb-shaped pouches in the bowel wall, resulting from the tissue in the gut bulging outward under pressure.
Of course, the way we go to the toilet is not the only cause of hemorrhoids and diverticula; however, it remains a fact that the 1.2 billion people in this world who squat have almost no incidence of diverticulosis and far fewer problems with hemorrhoids. We in the West, on the other hand, squeeze our gut tissue until it comes out of our behinds and we have to have it removed by a doctor. Do we put ourselves through all that just because sitting on a throne is more “civilized” than silly squatting? Doctors believe that straining too much or too often on the toilet can also seriously increase the risk of varicose veins, a stroke, or defecation syncope—fainting on the toilet.
A text message I received from a friend who was on holiday in France read, “The French are crazy! Someone’s stolen the toilets from the last three service stations we stopped at!” I had to laugh, first, because I suspected my friend was actually being serious, and second, because it reminded me of my first experience of French squat toilets. “Why am I being forced to squat here when you could just as easily have put in a proper toilet?” I mournfully complained to myself as I recovered from the shock of the emptiness I saw before me. Throughout much of Asia, Africa, and southern Europe people squat briefly over such toilets in a kind of martial arts or downhill skiing pose to defecate. We, by contrast, take so long, we have to while away the time until we’ve finished our business with reading the paper, carefully prefolding pieces of toilet paper for imminent use, scanning the corners of the bathroom to see if they could do with a clean, or staring patiently at the opposite wall.
When I read this chapter out to my family in our living room, I looked up to see disconcerted faces. Are we going to have to descend from our porcelain thrones and squat precariously over a hole to poop? Of course not, hemorrhoids or no hemorrhoids! That said, it might be fun to try climbing up onto the toilet seat to do our business while squatting there. But there’s no need for that, either. It is possible to squat while sitting. It’s a particularly good idea when things don’t come so easily, so to speak. To do it, just incline your upper body forward slightly and put your feet on a low footrest placed in front of the toilet, et voilá!—all the angles are correct, and you can read the paper, prefold your tissue, or stare at the wall with a clear conscience.
The Gateway to the Gut
YOU MIGHT THINK that the back end of the gut has so many surprises in store for us because it is something we do not think about very much. But I don’t think that’s the real reason. The other end of the gut, the gateway, so to speak, also has no shortage of surprises in store—even though we are directly confronted with it every morning when we clean our teeth.
You can seek out these secrets with your tongue. These are four small points in your mouth. Two of them are located on the inside of your cheeks, opposite your upper molars, more or less in the middle. If you explore the area with your tongue, you will feel two tiny bumps. If they notice them at all, most people assume they must have bitten themselves in the cheek at some point, but they haven’t. These little nubs, which doctors call the parotid papillae, are found in the same position in everybody’s mouth. The other two points are lurking beneath your tongue, just to the right and left of the lingual frenulum, the fold of skin connecting your tongue to the floor of your mouth. These four little nubs supply your mouth with saliva.
The papillae in your cheeks secrete saliva whenever it’s needed right away—for example, when we eat. The two tiny openings under the tongue secrete saliva continuously. If you could somehow enter these channels and swim against the tide of saliva, you would eventually reach
the main salivary glands. They produce the most saliva—about 11/2 to 2 US pints (0.7 to 1 liter) a day. If you feel upward from your neck to your cheek, you will notice two soft, round raised areas. May I introduce you? They are the bosses.
THE SUBLINGUAL PAPILLAE, those two constant suppliers of saliva, are situated right behind our lower front teeth, which are particularly susceptible to the buildup of tartar. This is because there are substances in our saliva that contain calcium whose sole function it is to make our teeth harder. But if a tooth is constantly bombarded with calcium, it can be a case of too much of a good thing. Tiny molecules floating innocently by are caught up and “fossilized” without so much as a by-your-leave. The problem is not the tartar itself, but the fact that it has such a rough surface, affording a much better foothold for bacteria that cause tooth decay and gum disease than smooth, clean tooth enamel.
But what are fossilizing, calcium-containing substances doing in our saliva? Saliva is basically filtered blood. The salivary glands sieve the blood, keeping back the red blood cells, which are needed in our arteries, not in our mouth. But calcium, hormones, and some products of our immune system enter the saliva from the blood. That explains why each person’s saliva is slightly different. In fact, saliva analysis can be used to test for diseases of the immune system or for certain hormones. The salivary glands can also add extra substances, including those calcium-containing compounds, and even natural painkillers.
Our saliva contains one painkiller that is stronger than morphine. It is called opiorphin and was only discovered in 2006. Of course, we produce only small amounts of this compound, otherwise we would be spaced out on our own spit all the time! But even a small amount has a noticeable effect, since our mouth is such a sensitive thing. It contains more nerve endings than almost anywhere else in the human body. Even the tiniest strawberry seed can drive us crazy if it gets stuck somewhere. We feel every grain of sand in a badly washed salad. A teeny little sore, which we would not even notice if it were on our elbow, hurts like hell and feels monstrously big in our mouth—without our salivary painkiller, it would feel even worse!
When we chew, we produce more saliva and with it more of such analgesic substances, which explains why a sore throat often feels better after a meal and even minor sores in the oral cavity hurt less. It doesn’t have to be a meal—even chewing gum provides us with a dose of our oral anodyne. There are even a handful of new studies showing that opiorphin has antidepressant properties. Is our spit partly responsible for the reassuring effects of comfort eating? Medical research into both pain and depression may deliver the answers in the next few years.
Saliva protects the oral cavity not only from too much pain, but also from too many bad bacteria. That’s the job of mucins, for example. Mucins are proteins that form the main constituent of mucus. They help provide hours of fascination and fun for young children who have just found out they can blow bubbles with their own spit. A more useful function is their ability to envelop our teeth and gums in a protective mucin net. We shoot them out of our salivary papillae like Spider-Man shoots webs from his wrists. These microscopic nets can catch bacteria before they have a chance to harm us. While the bad bacteria are caught in the net, antibacterial substances in our saliva can kill them off.
Like the natural painkillers in our saliva, bactericidal substances are present in our saliva in small concentrations. Our spit is not supposed to disinfect us completely. In fact, we actually need a core team of good little creatures in our mouth. Benign bacteria in the mouth are not totally wiped out by our disinfectant saliva since they take up space—space that could otherwise be populated by more dangerous germs.
When we are asleep, we produce very little saliva. That’s good news for those who tend to drool into their pillow. If they produced the full daytime quota of 2 to 3 US pints (1 to 1.5 liters) during the night, too, the results would not be particularly pleasant. The fact that we produce so little saliva at night explains why many people have bad breath or a sore throat in the morning. Eight hours of scarce salivation means one thing for the microbes in our mouth—party time! Brazen bacteria are no longer kept in check, and the mucus membranes in our mouth and throat miss their sprinkler system.
That is why brushing your teeth before you go to bed at night and after you get up in the morning is such a clever idea. Brushing at bedtime reduces the number of bacteria in your mouth, leaving fewer partygoers for the all-night bash. Brushing in the morning is like cleaning up after the party the night before. Luckily, our salivary glands wake up at the same time we do in the morning and start production straight away. Munching on our first piece of toast or performing our morning dental hygiene duties adds extra stimulation for salivation, and this washes away the nocturnal microbes or transports them down into our stomach, where our gastric juices finish them off.
Those who suffer from bad breath during the day may have not managed to remove enough musty-smelling bacteria. Those cunning little critters love to hide out under the newly formed mucin net, where the antibacterial substances in our saliva cannot get to them. A tongue scraper can help here, but so can chewing gum, which helps stimulate saliva production to swill out those mucin hideouts. If none of this helps, there is another place where the causes of bad breath can lurk—but more of that later, after we have found out about the second secret place in our mouth.
This place is one of those typical surprises—like when you think you know someone, only to find out they have an unexpected crazy side to them. The well-coiffed secretary from Chicago who turns up on the Internet as a fanatical ferret breeder. The heavy-metal guitarist seen buying skeins of yarn because he finds knitting so relaxing and it’s such a good workout for the fingers. The best surprises come after first impressions have been made, and the same is true of your own tongue. When you look in the mirror and stick out your tongue, you are not seeing it in all its glory. You might well ask how it looks farther down, as you can clearly see that it does not just end at the back of your mouth. In fact, the root of the tongue is where things start to get really interesting.
The root of the tongue is home to an alien landscape of pink domes. Those whose gag reflex is not too pronounced can carefully feel the root of their tongue with a finger. When you reach the root, you will notice it gets pretty bumpy back there. The job of these nodules—doctors call them your lingual tonsils—is to investigate everything we swallow. To do this, they pick up tiny particles of anything we eat, drink, or inhale and draw them into the nodule. Inside, an army of immune cells waits to receive training in how to deal with foreign substances invading from the outside world. They need to learn to leave bits of apple in peace, while attacking anything that might give us a sore throat. So, if you do explore the root of your tongue with your finger, it is not clear who is explorer and who the explored. After all, this area includes some of the most inquisitive tissue in our body—immune tissue.
The immune tissue at the base of the tongue, also called the lingual tonsils.
The immune tissue has a number of such inquisitive hotspots. Strictly speaking, a ring of immune tissue encircles our entire throat. Known to scientists as Waldeyer’s tonsillar ring, it includes those lingual tonsils at the bottom of the circle; the palatine tonsils—these are the ones we generally think of as our tonsils—at either side; and at the top of the ring, where the ear, nose, and throat areas meet, there is more such tissue. (When swollen and infected, especially in children, this is what we know as adenoids.) Those who believe they have no tonsils left are not quite correct. The entire collection of tissue in Waldeyer’s ring makes up our tonsils. Whether they are located at the root of the tongue, at the back of the mouth, or at the side of our throat, all these areas of tonsillar tissue do the same job: they inquisitively investigate any foreign substance they encounter and use the information to train the immune system to defend us.
The tonsils—the ones we often have removed—are just not as clever in the way they go about this task. Rather than forming
bumps, they tend to form deep grooves (to increase surface area) known rather spookily as “crypts.” Sometimes, too much foreign material can get caught in the crypts, leading to frequent infections. This is a side effect, so to speak, of having overinquisitive tonsils. So, if the tongue and teeth have been excluded as a cause of a patient’s bad breath, the next place to check is the tonsils—if they are still there.
Sometimes, little white stones can be found hiding in the crypts, and these stones smell terrible! Often, people have no idea they are there, and they spend weeks trying unsuccessfully to get rid of bad breath or a strange taste in their mouth. No amount of tooth brushing, tongue scraping, or gargling helps. The little stones will eventually work their way out of their hiding places, with no permanent harm done. But you can also take fate into your own hands and, with a little practice, squeeze them out. That done, bad breath problems disappear instantaneously.
Gut: The Inside Story of Our Body's Most Underrated Organ (Revised Edition) Page 2