Immune: A Journey Into the Mysterious System That Keeps You Alive

by Philipp Dettmer

The microorganisms that are causing infectious diseases are comparatively new to our biology. Our bodies and immune systems did not have hundreds of thousands of years to evolve alongside them. Surviving the measles does not make you tougher, it just makes your life bad for two weeks. And if your immune system is not in good shape it might also just kill you. Dangerous pathogens are, well, dangerous.

Coughing into your elbows, washing your hands regularly and properly, and wearing masks buys us time for larger-scale interventions, like vaccines or medication. Hygiene reduces our need to prescribe antibiotics, which automatically combats antibiotic resistance. It protects the weaker members of society like small children and seniors, the immunocompromised, people going through chemotherapy or suffering from genetic defects.

what is the cause of the sharp rise of immune defects in the last fifty years? Well, here it may become counterintuitive because it all has to do with microbes but in a different way. It seems that to train your immune system you need to hang out with harmless friends. Your immune system needs nice playdates to learn when to be gentle and forgiving. This more nuanced version of looking at interactions with the microbes around us has been called a few different names, but the nicest one may be the “Old Friends” Hypothesis, which focuses much more on our evolution.

we mentioned that you are a biosphere, surrounded by invaders that want to get in. But you are so much more. You are also an ecosystem where microorganisms of all kinds live together with you.

These communities of commensal microorganisms are as essential to your survival and health as any of your organs. And one of their most important jobs is to train your immunity.

When you are born, your immune system is like a computer. It has hardware and software and is in theory able to do a lot of things. But it doesn’t have a lot of data. It needs to learn which programs it needs to run and when. Who is a foe and who can be tolerated. So for the first few years of your life it collects information from its environment. It collects data from the microorganisms it encounters.

And there is a huge difference between Amish and Hutterites: While the Amish practice a traditional style of farming, where single families have their own farms with dairy cows and horses that are used for field work and for transportation and in general avoid modern technology, the Hutterites live on large and industrialized communal farms, with industrial machines and vacuums and many amenities of the modern world. Consequently, researchers found a much higher rate of microbes and microbe poop in the houses of the Amish compared to the Hutterites. The rates of asthma and other allergic disorders are four times higher in Hutterites than in the Amish. So it seems growing up in a less-urban environment offers some protection against allergic disorders.

As we said, until very recently in human history, people lived in houses made from natural materials like wood, mud, and thatch, all full of microbes that were all too familiar to our immune systems.

The microbiome of small children varies significantly depending on how they were born.

Both C-sections and the lack of breastfeeding are correlated with a higher rate of immune disorders like allergies.

Fiber is an important power food for a lot of useful and friendly commensal bacteria, and the fact that we just eat less and less of it means that we can’t sustain these little bacteria buddies in the numbers that we might need them.

All of these factors together probably made for the less than ideal situation we have today.

So what can you take away from this chapter? Wash your hands at least every time you use the restroom, clean your apartment but don’t try to sterilize it, and clean the tools you use to prepare food properly. But let your kids play in the forest.

the notion that “natural is better” is something only people who are not actually living in nature can say, and who have forgotten why our ancestors worked so hard to escape it.

Boosting the

Immune System is a horrible idea that is used by people trying to make you buy useless stuff!

Over everything else, you want a balanced immune system. Homeostasis. Aggression and calmness. You want elegant dancers who remember the choreography really well over pumped-up rugby players who want to smash stuff. In all likelihood, your immune system works exactly as intended.

At least for now, there are no scientifically proven ways to directly boost your immune system with any products

The most important thing you need to do to have a healthy immune system is to eat a diet that provides you with all the vitamins and nutrients your body needs. The reason is, simply, your immune system constantly makes many billions of new cells. And all these newborn cells need resources to function properly. Malnutrition is strongly associated with a weak immune system. If you are starving, you are more susceptible to infections and diseases because your body has to make hard decisions and the immune system suffers from that.

On top of just eating right, the positive health effects of even moderate regular exercise have been known for a long time. Your body is made for movement and so moving it

around a bit keeps a variety of systems in good health, especially your cardiovascular system. Working out also directly boosts your immune system, because it promotes good circulations of fluids throughout your body. In a nutshell, just by moving, stretching, and squashing your various body parts, your fluids flow better and more freely than if you lie on your couch all day. And good circulation is good for the immune system because it allows your cells and immune proteins to move more efficiently and freely, which makes them do their job better.

If you feel like you have a shortage of a vitamin or microelement or something, this is something you should discuss with your doctor in real life.

If you want to “boost” your immune system so that it is healthy, start by taking better care of yourself by living a healthy lifestyle, and the complex concert of your immune system, with all its billions of different parts, will run properly for a longer time.

Unfortunately there are millions of people who suffer from real and serious diseases that are anything but funny, from cancer to autoimmunity.

far as to disregard real medical treatment as a consequence of these lies supported by greed or well-meaning but ill-advised appeals to naturalism.

The trial was supposed to look for side effects in humans taking a drug that was supposed to stimulate T Cells in cancer patients and make them survive longer.

So the idea of TGN1412 is pretty straightforward: Give T Cells an artificial “kiss” to stimulate them to be more effective and easier to activate in cancer patients.

But instead, minutes after TGN1412 was given to healthy young men, all hell broke loose. It turned out macaques, the animals used to test the drug in animal models, happen to have way fewer CD28 molecules on their T Cells than humans and so they reacted way less strongly to the drug than expected, creating a false sense of security. Also, for some reason the drug was administered ten times faster to the human volunteers than it had been in the animal model.*

As the TGN1412 trial failed in the most horrible way possible, it obviously sent shockwaves through the medical research community. Many guidelines for human trials were amended as a consequence of this.

Make no mistake—while we did discuss a lot of things in this book, I still massively simplified everything. We barely scratched the surface from the perspective of actual immunologists that are working in the trenches of immunology.

OK, so boosting and strengthening the immune system is complicated for experts, and outside of a healthy lifestyle is pretty impossible (and ill-advised) for regular people. But there is actually a huge thing you could do to at least prevent damage. It turns out that many people are actually suppressing their immune system without being aware of it.

There are all kinds of drugs that heal mice or prolong their lives and do whatnot—but do nothing at all for humans. Or worse, they are dangerous or even deadly for us. So again, this is not saying that these experiments are not critically important, unbelievably important knowledge has been gained through animal models. But when it comes to drugs and cures, everything can be different once a drug is used by humans. So if you hear news about some kind of amazing drug, make sure to check if the excitement is based on human trials or if it is still in an earlier stage, tested in animals.

So for your ancestors it was a good idea to react strongly to perceived danger because if you acted decisively, then you were more likely to survive—if you were wrong and something was not actually dangerous nothing was lost.

good at responding rapidly to a possible source of danger, a stressor, real or not, were more successful at surviving and reproducing than others who were not.

In mammals for example, this meant glands that are able to rapidly release stress hormones, which accelerated the delivery of oxygen and sugar to the heart and skeletal muscles and made it possible to react to a threat instantly and with power.