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May 16 - May 29, 2019
Patients with intestinal disease who also suffer from extreme anxiety or depressive disorders are often recommended antidepressants by their doctor. However, they are rarely told why. And there is a simple reason for that: no doctor or scientists knows.
messages in all directions in a pubescent brain. This process is not complete until we reach the age of about twenty-five. After that, nerves react according to well-rehearsed patterns. Patterns that have proved useful in the past are retained; others are rejected as failures. This explains the disappearance not only of the inexplicable fits of laughter and temper tantrums of the teenage years, but also of the posters plastering the bedroom walls. After this age, we find it more difficult to deal with sudden change, but the payback is a more stable, calmer disposition. This can also result in
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If it is the case that antidepressants increase neuroplasticity, they may work by loosening up such negative thought patterns. This is most beneficial when accompanied by effective psychotherapy to help patients resist slipping back into old habits.
95 percent of the serotonin we produce is manufactured in the cells of our gut, where it has an enormous effect on enabling the nerves to stimulate muscle movement and acts as an important signaling molecule.
Anyone who suffers from anxiety or depression should remember that an unhappy gut can be the cause of an unhappy mind. Sometimes, the gut has a perfect right to be unhappy—if it is dealing with an undetected food intolerance, for example. We should not always blame depression on the brain or on our life circumstances—there is much more to us than that.
Of our entire microbiome—that is, all the micro-organisms that teem on the inside and outside of our bodies—99 percent are found in the gut. Not because there are so few elsewhere, but because there are simply so inconceivably many in the gut.
Our gut’s microbiome can weigh up to 4½ pounds (2 kilos) and contains about 100 trillion bacteria. One-thirty-second of an ounce (1 gram) of feces contains more bacteria than there are people on Earth.
In general, it is accurate to say that the number of bacteria is smaller in the upper sections of the digestive tract, while a very, very large number reside in the lower parts, such as the large intestine and the rectum.
The vast majority of our immune system (about 80 percent) is located in the gut. And with good reason. This is where the main stage at the bacterial Woodstock is situated, and any immune system worth its salt must be there or be square.
However, we cannot receive blood from donors whose blood cells have a different blood-group marker on their surface. It would immediately remind our immune system of bacteria, and since the immune system knows that bacteria have no business being in the bloodstream, it would consider the donated blood cells an enemy and cause the cells to form clumps.
This effect is known as colonization resistance. The majority of the microbes in our gut protect us simply by occupying spaces that would otherwise be free for harmful bacteria to colonize.
Some of those questions might be answered with the help of a group of germ-free mice in a New York laboratory. They are the cleanest creatures in the world: they come into the world via sterile cesarean births, they live in antiseptic cages, and they eat steam-sterilized food. Disinfected animals like these could never exist in nature.
The mice allow researchers to watch what happens to an immune system that has nothing to do. What goes on in a gut with no microbes? How does an untrained immune system react to pathogens? What differences are so obvious they can be seen by the naked eye?
As soon as there is any breach in the protective amniotic sac, colonization begins. While 100 percent of the cells that make us up when we start life are human cells, we are soon colonized by so many microorganisms that only 10 percent of our cells are human, with microbes accounting for the remaining 90 percent.
The idea that the bacteria in our gut might influence our overall metabolism, and therefore our weight, is only a couple of years old. The basic concept is that bacteria do not steal anything from us when they share our food in this way.
The farther you travel from the small intestine toward the final exit from the gut, the more bacteria you will find per square inch of gut membrane.
Molecules of the two kinds of lactic acid are mirror images of each other. Feeding the human digestive system with levorotatory lactic acid molecules is like giving a left-handed pair of scissors to a right-handed person: they’re hard to handle. That is why it is a good idea to pick yogurt from the supermarket shelves that states on the container: “Contains mainly dextrorotatory [or right-turning] lactic acid.”
In the industrialized world, about 90 percent of our nutrition comes from what we eat, and we are fed about 10 percent by our bacteria.
In other words, if we are concerned about our weight, we need to think about more than just the big, fat calories we consume and remember that our bacteria are at the dinner table with us.
The gut flora might include too many bacteria that program a person for chubbiness. These chubbiness-inducing bacteria are efficient at breaking down carbohydrates.
Skinny mice excrete a certain quantity of indigestible calories while their overweight peers excrete significantly fewer. The chubby bacteria in the latter group extract every last smidgen of energy from the same amount of food and cheerfully feed it to Mr. or Ms. Mouse.
A banana is less likely to make you fat than half a chocolate bar containing the same number of calories. That is because plant carbohydrates are more likely to attract the attention of bacteria that provide fatty acids to local customers like the liver. The chocolate bar, on the other hand, is more likely to attract the attention of the full-body feeders.
Patients who have metabolic problems, such as obesity, diabetes, and high blood-lipid levels, usually have slightly increased levels of infection markers in their blood, too.
Rule number one: Always use plastic chopping boards because they are easier to clean properly and provide fewer grooves and ridges for bacteria to hide in.
Rule number two: Always wash anything that comes into contact with raw meat or eggshells thoroughly with hot water—chopping boards, hands, cutlery, kitchen sponges, and colanders, for example.
Rule number three: Whenever possible make sure that meat and egg-based foods are cooked through.
One out of four North Americans is a carrier for H. pylori. Not everyone who carries it in their stomach is doomed to develop stomach problems, but most people who do have stomach problems have H. pylori to thank for their woes.
A new product could soon provide an alternative to antibiotics: sulforaphane, which is contained in broccoli and similar vegetables. This substance is able to block the enzyme that H. pylori uses to neutralize gastric acid.
The stomach has a battery of stem cells, which constantly replace lost cells. If these replacement manufacturers are overworked, they may begin to make mistakes. Cancer cells are the result. Statistically, this does not look too serious: around 1 percent of H. pylori carriers develop stomach cancer. But if you bear in mind that half of humanity harbor these bacteria in their stomach, 1 percent turns out to be a pretty big number. The probability of developing stomach cancer without the presence of H. pylori is about forty times less than with it.
Toxoplasmata are the reason your cat’s litter should be changed every day if there is a pregnant woman in the house (but not by her!), why raw food should be avoided by mothers-to-be, and why fruit and vegetables should always be washed.
Strangely, we can dream all sensory experiences except smells. Our dreams are always odorless.
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.
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.
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.
Thirty years ago, about one person in ten had an allergy. Today that figure is one in three.
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 si...
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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.
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.
Bacteria cannot breed on dry surfaces. Some cannot survive there at all.
The optimum temperature for your fridge is something below 41 degrees Fahrenheit (5 degrees Celsius).
However, damp kitchen cloths, a load of underpants, or sick people’s laundry should be washed at 140 degrees Fahrenheit (60 degrees Celsius) or more. Most E. coli bacteria are killed by temperatures above 104 degrees Fahrenheit (40 degrees Celsius), and 158 degrees Fahrenheit (70 degrees Celsius) is enough to kill off tougher Salmonella bacteria.
In principle, we use the same system when we use hand cream. We trap microbes in a film of fat and hold them captive there. When we wash the film off, we rinse the bacteria away with it. Since our skin produces a natural coating of fat, soap and water are often enough to achieve this effect. Some of the fat layer remains, aiding its replenishment after washing. Too frequent hand washing makes no sense—and the same is true of too frequent showering. If the protective fat layer is rinsed away too often, our unprotected skin is exposed to the environment. That gives odor-producing bacteria a
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The researchers are attempting to use bacteria to combat body odor. They disinfect volunteers’ armpits, spread them with odorless bacteria, and start the stopwatch. After a couple of minutes, the subjects are allowed to put their shirts back on and go home. The volunteers return repeatedly to the laboratory, where experts sniff their armpits. The initial results are quite promising—the
The main reason for taking them is colds. This is like a knife in the heart of any microbiologist. Colds are often not even caused by bacteria, but by viruses! Antibiotics
They have no effect on viruses at all. So taking antibiotics to cure a cold is usually a complete waste of time.
The senseless use of antibiotics does, however, kill many helpful bacteria, which can be harmful in itself.
To avoid this, doctors can perform a procalcitonin test, which indicates whether cold-like symptoms are caused by a bacterial or viral infection. The test can be especially helpful to make sure children don’t take antibiotics unnecessarily.
Research in Sweden showed that the gut bacteria of children were still significantly altered two months after taking antibiotics. Their guts contained more potentially harmful bacteria and fewer beneficial types like Bifidobacteria and Lactobacilli.
