Toxoplasma gondii could, therefore, influence us via the fear, smell, and behavioral centers of the brain. A higher risk of being involved in an accident, attempting suicide, or suffering from schizophrenia indicates that an infection affects at least some of us. It will take some time before discoveries like these have consequences for standard medical practice. Suspicions need to be scientifically proven and further research into possible treatments is needed. This insistence of science on time-consuming validation processes can cost lives. Antibiotics, for example, did not appear in our pharmacies until decades after they were discovered. But this caution can also save lives. Thalidomide and asbestos could easily have been tested for a little bit longer before entering the market.
Toxoplasmata can influence us far more than we would ever have thought possible just a few years ago. And they have rung in a new scientific age. An age in which a crude lump of cat feces can show us how susceptible our lives are to change. An era in which we are just beginning to understand just how complex the connections are between us, our food, our pets, and the microscopic world in, on, and around us.
Is this spooky? Well, maybe a little bit. But isn’t it also exciting to see how we are gradually decoding processes that we used to believe were part of our inescapable destiny? This could help us to grab the risks by the horns and defy them. Sometimes, it takes nothing more than a scoop of cat litter, a well-cooked chicken, and properly washed fruit and veggies.
Pinworms
THERE ARE SOME little white worms that like to live in our gut. Over many centuries, they have adapted their behavior to live with us. Half the world’s population has had a visit from these worms at some time or other. Some people never even notice. For others, it’s an embarrassing infestation they’d rather not talk about. If you look at just the right moment, you can even see them giving us a wave out of the anus. They are 0.2 to 0.4 inches (5 to 10 millimeters) long, and white, and they sometimes have a pointed end. They look a little like the vapor trails left by jets in the sky except they don’t get longer and longer. Anyone who has a mouth and a finger can get these parasites, which are also known as threadworms. Finally, there’s an advantage to being fingerless and/or mouthless!
Let’s put the cart before the horse, or rather, the worm. A lady-worm looking for a place to lay her eggs wants to make sure they will have a secure future. And such a place is not so easy to reach. A pinworm egg has to be swallowed by a human being, then hatch in the small intestine so that it can reach the large intestine by the time it is a grown-up worm. But our mother-worm-to-be lives in the lower reaches of the digestive tract with everything moving in the wrong direction for her needs. So she wonders how she is ever going to get back to her host’s mouth to give her eggs the start in life that they need. Here she makes use of the only kind of intelligence such a creature has at her disposal—the intelligence of adaptation. Whether this is the origin of the word “brown noser” or not is open to question.
Female pinworms know when we are still, lying down, and too comfortable to rouse. That’s exactly when they set off toward the anus. They lay their eggs in the many little creases around the anus and wriggle around until it starts to itch. They then slip quickly back inside the gut, because experience has taught them that soon a hand will appear and finish off the job. Under the bedclothes, the hand heads for the backside, targeting that itch. The same neural pathways that passed on the itch now give the instruction to scratch. We obey the instruction, thereby providing the pinworm’s children with an express connection to the mouth area.
When are we least likely to go and wash our hands after scratching our behind? When we are oblivious to all this action because we are asleep or too sleepy to get up and head for the bathroom. And that is pinworm egg-laying time. It’s clear what that next dream about sticking your finger in a yummy chocolate cake will mean. It will mean that those eggs are heading to their ancestral home: your mouth. That might sound gross, but it’s not so very different from eating chickens’ eggs. Only chickens’ eggs are bigger and usually cooked.
Organisms that move into our gut uninvited and implement their plans for progeny there get a bad rap from us. And we often avoid talking about them with others. It’s as if we feel we have been a bad manager for our body, failing to lay down the law properly and letting any old strangers take up residence without interviewing them first. But pinworms are not just any old strangers. They are guests who wake the manager in time for morning exercises and then give their host a massage to stimulate the immune system. Furthermore, they steal very little of our food.
It is not good to keep these parasites as permanent guests, but once in a lifetime is fine. Scientists suspect that when kids have had worms, they are less likely to contract severe asthma and diabetes in later life. So welcome, Mr. and Mrs. Pinworm, come on in! But don’t outstay your welcome, please. An uncontrolled attack of worms can have three rather unwelcome consequences.
1.Lack of a good night’s sleep can lead to concentration problems, nervousness, or irritability during the day.
2.What the worms don’t want is to lose their way—and we don’t want them to either. When worms get into places they don’t belong, they have to go. Who wants a pinworm with a bad sense of direction, after all?
3.Sensitive guts, or those containing overactive worms, can become irritated. Worms have a tendency to cause irritation anyway. There are many problems this can cause: not going to the toilet often enough, going to the toilet too often, abdominal cramps, headaches, nausea, or none of the above.
If a worm host has any of these symptoms, a visit to the doctor is essential! The doctor will ask you to put sticky tape to a use you never learned in arts and crafts lessons in elementary school. Some doctors are more charming about it than others, but, in essence, what they will tell you to do is to spread your cheeks, stick tape to your anus and the surrounding area, pull it off again, bring it to the surgery, and hand it over to the receptionist.
Worm eggs are small and round and adhere well to sticky tape. Searching for eggs on Easter Sunday morning would be a lot more efficient if you had a great big egg-magnet that attracted all the eggs from the garden. Since worm eggs are so much smaller than Easter eggs, it makes sense to use a trick like this. The sticky-tape egg hunt has to take place in the morning, as that’s when most eggs are there. And it is not a good idea to flush out or sweep clean the worm garden before you hunt for the eggs. So the first thing that comes into contact with the region in the morning should be those strips of sticky tape.
The doctor will examine the fruits of your labors under the microscope, hunting for little oval eggs. If they are already developing into larvae, they will have a line down the middle. The doctor can then prescribe the right medication and your pharmacist will help you win the battle to get rid of your unwanted guests. The typical medication prescribed—let’s call it mebendazole for the sake of argument—works on the tit-for-tat principle we all know from kindergarten: if you bother my gut, I’ll bother yours.
The medication makes its way from mouth to rectum and meets our renegade squatters along the way. Mebendazole is much more harmful to a worm’s gut than it is to ours. It places the worms on a forced diet, denying them all access to sugar. Sugar is the stuff of life for worms, so this will be the last diet they ever go on. It’s a bit like trying to get rid of unwanted guests by not offering them anything more to eat.
Pinworm eggs live for a long time. If you have worms and can’t keep your hands away from your mouth, you should at least try to reduce the number of eggs in the area to a minimum. Bedclothes and underwear should be changed every day and washed at 140 degrees Fahrenheit (60 degrees Celsius) or hotter, regular hand washing is essential, and intense itching might be better treated with creams than by scratching. My mother is convinced that worms can be eliminated by swallowing a whole clove of garlic once a day. I have not been able to find any scientific studies to prove this, but nor are there any studies about what temperature necessita
tes the wearing of warm jackets and my mother is always right about that! If all this fails, do not despair. Go back to your doctor and be proud of having such an inviting gut.
Of Cleanliness and Good Bacteria
WE ALWAYS WANT to protect ourselves from harm. Few people would choose to have Salmonellae or a nasty H. pylori. Even though we have not yet identified them all, we know already that we’d rather not have chubby bacteria or microbes that cause diabetes or depression. Our greatest protection against them is cleanliness. We are careful about eating raw food, kissing strangers, and washing our hands to rid them of anything that might spread disease. But cleanliness is not always what we imagine it to be.
Cleanliness in our gut is something akin to cleanliness in a forest. Even the most conscientious of cleaners would not dream of taking a mop to the forest floor. A wood is clean if the beneficial plants it contains are in healthy equilibrium. We can help the forest along by sowing seeds and hoping new plants will take root. We can identify favorite or useful plants in the forest and nurture them to help them grow and multiply. Sometimes, there are nasty pests. Then, careful consideration is in order. If the situation is desperate, chemicals might be the answer. As their name implies, pesticides are great at killing pests, but it is not a great idea to spray them round like air freshener.
Clever cleanliness begins with our everyday routines—but what is well-advised caution and what is excessive hygiene? There are three main tools for keeping our insides clean. Antibiotics can rid us of acute pathogens, while prebiotic and probiotic products can promote beneficial elements. Pro bios means “for life.” Probiotics are edible living bacteria that can make us healthier. Pre bios means “before life.” Prebiotics are foodstuffs that pass undigested into the large intestine, where they feed our beneficial bacteria so that they thrive better than bad bacteria. Anti bios means “against life.” Antibiotics kill bacteria and are our saviors when we have picked up a pack of bad bacteria.
Everyday Cleanliness
THE FASCINATING THING about cleanliness is that it is mostly in the head. A peppermint tastes fresh, clean windows look clear, and we love slipping into a freshly made bed after a hot shower. We like the smell of clean things. We like to run our hands over smooth, polished surfaces. We find comfort in the idea that we are protected from an invisible world of germs if we use enough disinfectant.
In Europe 130 years ago, it was discovered that tuberculosis is caused by bacteria. This was the first time the public took notice of bacteria—and they were seen as bad, dangerous, and, most worryingly, invisible. It was not long before new regulations were introduced in European countries: patients were isolated so they could not spread their germs; spitting was forbidden in schools; close physical contact was discouraged; and warnings were issued against “the communism of the towel!” People were even advised to limit kissing to “the erotically unavoidable.” That might sound funny to us today, but those ideas put down deep roots that can still be felt in our modern Western society: spitting is still frowned upon, we are still reluctant to share towels and toothbrushes, and we keep a greater physical distance in our dealings with others than most cultures.
Preventing deadly disease by banning pupils from spitting at school seemed like a simple and effective idea. We internalized it in our culture as a social rule. Those who did not comply were despised as a danger to everyone’s health. This attitude was passed on from parent to child, and public spitting became a social taboo. Cleanliness really was thought to be next (in importance) to godliness; people craved a sense of order in a life full of chaos. The anthropologist Mary Douglas summed this up in her book Purity and Danger with the phrase, “Dirt is matter out of place.”
Bathing as a way of keeping the body clean was a privilege of the rich even up to the beginning of the twentieth century. It was around that time that dermatologists in Germany began to call for “a bath a week for every German!” Large companies built bathhouses for their employees and encouraged personal hygiene by issuing them with free towels and soap. The tradition of the weekly bath did not really take hold until the 1950s. Then, typical families took their bath on a Saturday evening, one after another in the same bathwater, and hard-working Dad often got to go in the tub first. Originally, personal cleanliness meant ridding the body of unpleasant smells and visible dirt. As time went on, this concept became increasingly abstract. It’s hard for us today to imagine this once-a-week family bathing routine. We spend money on disinfectants to get rid of things we can’t even see. The surface in question looks exactly the same after cleaning as it did before—yet just knowing it is clean is extremely important to us.
The news media tell us horror stories about dangerous flu viruses, multi-drug-resistant superbugs, and EHEC-contaminated food. When food contamination scares such as tainted salad recalls are in the news, some people react by giving up lettuce while others type “full body decontamination shower” into Google. Different people deal with fear in different ways. Dismissing this as hysteria is too easy. It makes more sense to try and understand where these fears come from.
Fear-driven hygiene involves attempting to clean everything away or kill it off. We don’t know what it might be, but we assume the worst. When we clean obsessively, we do indeed get rid of everything—both bad and good. This cannot be a good kind of cleanliness. The higher the hygiene standards in a country, the higher that nation’s incidence of allergies and autoimmune diseases. The more sterile a household is, the more its members will suffer from allergies and autoimmune diseases. Thirty years ago, about one person in ten had an allergy. Today that figure is one in three. At the same time, the number of infections has not fallen significantly. This is not smart hygiene. Research into Nature’s huge range of bacteria has led to a new understanding of what cleanliness should mean. It is no longer defined as the attempt to kill off potential dangers.
More than 95 percent of the world’s bacteria are harmless to humans. Many are extremely beneficial. Disinfectants have no place in a normal household. They are appropriate only if a family member is sick or the dog poops on the carpet. If a sick dog poops on the carpet, there are no holds barred—bring on the steam cleaners, disinfectant by the bucket-load, or a small flame thrower, perhaps. That might even be fun! But if the floor is just covered in dirty footprints, water and a drop of cleaning fluid are all you need. That combination is already enough to reduce the bacteria population of your floor by 90 percent, and it leaves the normal, healthy population of the floor a chance to recolonize the territory. What remains of any harmful elements is so little as to be negligible.
The aim of cleaning, then, should be to reduce bacteria numbers—but not to zero. Even harmful bacteria can be good for us when the immune system uses them for training. A couple of thousand Salmonella bacteria in the kitchen sink are a chance for our immune system to do a little sightseeing. They become dangerous only when they turn up in greater numbers. Bacteria get out of hand when they encounter the perfect conditions: a protected location that is warm and moist with a supply of delicious food. There are four recommended strategies for keeping them in check: dilution, temperature change, drying, and cleaning.
Dilution
DILUTION IS A technique we also use in the laboratory. We dilute bacteria with fluids and administer drops with different concentrations of bacteria to wax moth larvae, for example. Wax moth larvae change color when they get sick. That makes them a good indicator of the concentration of bacteria required to cause illness. For some, it’s a little as a thousand per drop of fluid, for others, as many as ten million.
One example of bacteria dilution in the home is washing fruit and vegetables. Washing dilutes most soil-dwelling bacteria to such a low concentration that they become harmless to humans. Koreans add a little vinegar to the water to make it slightly acidic and just that bit more uncomfortable for any bacteria. Airing a room is also a dilution technique.
If you dilute the bacteria on your plates, cutlery, and cutting board nicely with
water, then wipe them over with a kitchen sponge before putting them away, you may as well have licked them clean with your tongue. Kitchen sponges offer the perfect home for any passing microbe—nice and warm, moist, and full of food. Anyone looking at a kitchen sponge under the microscope for the first time usually wants to curl up on the floor in a fetal position, rocking back and forth in disgust.
Kitchen sponges should only be used for cleaning the worst of the dirt off. Plates, cutlery, and so on should then be rinsed briefly under running water. The same is true for dish towels or drying-up cloths if they never get a chance to dry out. They are more useful for spreading a nice even layer of bacteria on your utensils than for drying them. Sponges and cloths should be thoroughly wrung out and allowed to dry—otherwise they become the perfect place for moisture-loving microbes.
Drying
BACTERIA CANNOT BREED on dry surfaces. Some cannot survive there at all. A freshly mopped floor is at its cleanest after it has dried. Armpits that are kept dry by antiperspirants are less cozy homes for bacteria—and fewer bacteria produce less body odor. Drying is a great thing. If we dry food it keeps for longer before it rots. We use this to our advantage: just think of foodstuffs like pasta, muesli, crisp bread, dried fruit (such as raisins), beans, lentils, and dried meats.
Temperature
IN MANY PARTS of the world, the environment is refrigerated naturally once a year. From a bacteriological point of view, winter is the real spring clean! Refrigerating food is an extremely important part of our daily lives, but a fridge contains so much food that it remains a paradise for bacteria even at low temperatures. The optimum temperature for your fridge is something below 41 degrees Fahrenheit (5 degrees Celsius).
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