Considering everything our microbiome does to and for us, I’d like to ask: can we use it to create an improved version of ourselves? We just have to do it. After all, we are constantly changing our microbiome. If you change the ratio of plant and animal foods in your diet, reduce or increase alcohol consumption, then you are already changing it. You change your microbiome even when you use antibacterial soap or undergo antibiotic treatment. But what if you do it purposefully? What could microbial-oriented medicine be like? Try to think of the microbiome as your own lawn. Let it be a normal, healthy lawn, with even some variety — let’s say, in addition to grass, a little clover grows on it. To keep the lawn in order and to have more grass than clover, you will decide to apply fertilizer. And this is where prebiotics come on the scene.

It’s possible that you’ve never heard of them, but prebiotics are the same fertilizers for your microbes: they provide the latter with essential nutrients that favor certain species. Basically, prebiotics are soluble carbohydrates such as fructans (for example, inulin, lactulose and — delicious name! — galactooligosaccharide), which are part of some fruits and vegetables. These carbohydrates are enzymatically broken down by bacteria of the large intestine, such as Ruminococcus gnavus, to form short-chain fatty acids like butyrate, which provide nutrition to the cells of the intestinal lining.[2] By stimulating the development of beneficial microorganisms, prebiotics are believed to replicate some of the benefits of a natural high-fiber diet similar to that of our ancestors. Unfortunately, there is no single definition of prebiotics. According to the International Scientific Association for Probiotics and Prebiotics, prebiotics are “indigestible substances that provide beneficial physiological effects on the host body by selectively stimulating the predominant growth or activity of a limited number of bacteria inherent in a given organism.”3. Several randomized controlled clinical trials of prebiotics have been performed (such studies provide the most reliable results), and these trials have shown some success in the treatment of Crohn’s disease, constipation 6, and insulin resistance 7. However, most clinical trials are still at the stage of proving safety, and the number of participants is usually too small to draw reliable conclusions.

So, your lawn looked great for a while, but then something terrible happened: it was flooded with water or it was overgrown with weeds. What to do? Most likely, it will have to be selectively replanted. Probiotics are mostly bacteria that naturally live in the human gut or in fermented foods such as yogurt. These are mainly different types of lactic acid and bifidobacteria of the genera Bifidobacterium and Lactobacillus. Probiotics are living organisms that, when taken in certain amounts, are beneficial to health. They are also called “good” or “beneficial” bacteria. Probiotics can be purchased in the form of dietary supplements, lactic acid products, or suppositories. Some probiotic products contain a single strain of bacteria, while others contain a cocktail of different types of bacteria and fungi. The Food and Drug Administration (FDA) has not yet approved any applications for probiotic products, so they are now sold as dietary supplements in the United States. There have been quite a few clinical trials of probiotics, especially in recent years due to advances in microbiome decoding. The data proving the preventive and therapeutic effects of probiotics in the treatment of diarrhea in children 8 and irritable bowel syndrome in adults 9 can be considered the most reliable. There is also a prospect for the prevention and treatment of an acute intestinal disease of premature newborns — necrotizing enterocolitis. Other potential applications of probiotics include the treatment of obesity, lowering cholesterol levels, and regulating irritable bowel syndrome. Among the many possible effects of probiotics are the production of antimicrobial compounds and the restriction of harmful bacteria through competition for nutrients and prebiotics. Interestingly, probiotics do not have to survive to achieve a positive effect — sometimes they change bacteria simply by passing through the gastrointestinal tract.10 Today, the main problem is that there is much more hype and advertising around probiotics than there is reliable research. Have you had a chance to look into the food additives department in your supermarket lately? The organic food store next to my house in Boulder may be an atypical example, but it has an entire wall devoted to microbes that are supposed to be able to improve the condition of your intestines. Unfortunately, there is almost no real evidence that any of these strains will work. Although the principles according to which these strains were selected and isolated are quite convincing (for example, they produce short-chain fatty acids such as butyrate), in most cases they have not been proven to work. It is also unclear whether any living organisms still remain in the drug after transportation, storage and lying on a supermarket shelf; in order to survive, microorganisms need very specific conditions. The biggest problem is that many people believe that any probiotic is right for them. In any other situation, we are never so gullible. Imagine telling your friend or family member, “I didn’t feel well. But I’ve heard that medications help. And it’s true: I took the medicine, and I felt better.” Most likely, after that you will hear a number of clarifying questions: “What kind of medicine? Why this particular thing? Is there any evidence that this particular drug should be taken with your illness?” Or even: “Did you by any chance buy it from a dealer on the street?” When it comes to probiotics (or other microbiome-based drugs), such questions are usually not asked. I recently had a very similar conversation with a relative. She complained that she had unsuccessfully tried two types of probiotics in an attempt to cure irritable bowel syndrome (IBS), which developed after a large dose of antibiotics. I asked her on what principle she chose them, and I heard that one drug was recommended to her by some friend, and the second was recommended by a pharmacist at a pharmacy. I advised a relative to try a drug whose effect on IBS is confirmed by the results of a randomized controlled trial.11 She objected that this drug was much more expensive, but almost the next day she called and said that the new probiotic had helped her much better than the previous two. Now, a year later, this drug is still helping my relative cope with IBS. Of course, one example is not serious, but it only confirms that, before being treated, you still need to ask about scientific data. It is worth asking your doctor or pharmacist if they can recommend any probiotic that has successfully passed a randomized controlled trial (as already mentioned, the most reliable and reliable). If this is not possible, you can try to dig into scientific journals yourself (at the time of writing this book, there was not a single resource for patients where such data would accumulate). If that doesn’t work out, then fresh yogurt with live cultures definitely won’t hurt. However, there is evidence that different types of yoghurts also act in very, very different ways.12

Returning to the analogy with the lawn, sometimes there is nothing left but to remove the entire top layer and put a new turf. People with severe diseases of the gastrointestinal tract can literally ruin their whole lives and even die. One of these diseases is pseudomembranous colitis, which is caused by the spore—forming anaerobic microbe Clostridium difficile and is accompanied by persistent diarrhea. The patient has to go to the toilet dozens of times a day, and often there is even a threat to his life. In the United States, it is one of the most common nosocomial infections, affecting 337,000 people and killing 14,000 of them each year 13. Many people try to fight this disease with antibiotics, but most often they do not help. An addition or even an alternative to antibiotics is to transplant microbes from a healthy person to a patient. One of the radical experimental methods of treating pseudomembranous colitis is fecal transplantation. Yes, this is exactly what you thought: a healthy donor, most often a relative, provides a stool sample, an extract is prepared from it, which is then injected into the patient. There are two ways to do this: upper and lower. Both work effectively, healing 90% of patients. 14 The research I did in At the University of Minnesota, together with microbiologist Mike Sadowski and Dr. Alex Horuts, they showed that before starting treatment, the microbial community in the stool of patients with pseudomembranous colitis is radically different from the fecal communities of healthy people and resembles rather vaginal or skin communities. However, a few days after fecal transplantation, the intestinal communities of patients return to normal and all symptoms disappear. Fecal transplants allow the complete restoration of the intestinal microbial ecosystem. So far, this method has been used only for the treatment of pseudomembranous colitis. However, the success was so overwhelming that now scientists are actively interested in what other cases it can help. As already mentioned, laboratory experiments have shown that fecal transplantation can rid mice of obesity. It would be very tempting to try to apply these observations to the treatment of people.

Returning to the garden metaphor: can we make the lawn not hurt at all? Vaccination is the most effective method of health protection known to us. Vaccines reduce the risk of developing the disease by at least 90% 15, and since the beginning of their use, they have saved more human lives than any other innovation in the field of medicine, with the exception of drinking water purification. 16 Vaccines are humanity’s greatest public health triumph. As a rule, it is enough to introduce them once or several times in childhood in order to protect yourself from this disease for the rest of your life. Smallpox has been a scourge of mankind since at least the time of the Pharaohs 17, and it has killed or blinded many millions of people. But today it has been defeated thanks to vaccination 18. Vaccines are very selective: they teach your immune system to respond only to a specific type of bacteria — usually representatives of a specific strain — and do not target other, “beneficial” bacteria. So far, vaccines have been used primarily to fight specific pathogens, starting — for obvious reasons — with the most dangerous ones. But as the list of available vaccines expands, less deadly types of microbes become targets, including even those bacteria and viruses that can kill us only a few decades after infection (for example, human papillomavirus, or HPV, is a proven cause of cervical cancer). Since we are now beginning to learn about the role of certain bacteria in diseases that are not usually vaccinated against, perhaps it would be worthwhile to develop vaccines against them? How nice it would be, for example, if we could get rid of bacteria that secrete a chemical called trimethylamine-N-oxide, which leads to the development of cardiovascular diseases!19 Or from the bacteria Fusobacterium nucleatum, which are found in tumors of the large intestine,20 or even from those types of intestinal organisms that contribute to the very efficient — too efficient — extraction of energy from harmful foods and thus help to increase obesity.21 To date, these are just questions, but the prospects are endless. What about vaccination against depression or post-traumatic stress disorder (PTSD)? According to the World Health Organization, depression has now become the leading cause of disability in the United States and is spreading rapidly in developing countries. The spread of depression is paralleling the growth of other diseases traditionally considered “Western”, such as inflammatory bowel disease, multiple sclerosis and diabetes (and we already know that they all have both immune and microbial components). Can those soil bacteria that modulate the immune system and which we have lost contact with play a role? It has been experimentally proven that a soil bacterium Mycobacterium vaccae reduces anxiety levels in mice. Interestingly, in a situation of social stress (most often, a small mouse is put in a cage with a large dominant mouse that beats the new one), M. vaccae makes mice more resistant to stress, possibly outlining a model for treating stress disorders in humans.22 Graham Rook from University College London, along with Chuck Rayson, a psychiatrist from University of Arizona, and Chris Lowry, Professor of Integrative Physiology at At the University of Colorado, a few years ago, they proposed to create on the basis of M. vaccae is a vaccine for the treatment of depression. They have already obtained encouraging results in mice. Source: Rob Knight “Look what’s inside you”