We are made up of about 10 trillion human cells, but about a hundred trillion microbial cells live inside and on the surface of our body. Impressive numbers that make you think about what is included in the concept of the human “I”.
Microbes in incredible numbers live in every corner of our body. Health and even the character of a person depends on them. We offer to get acquainted with these tiny neighbors in order to know what to expect from them. We’ll adopt a book by Rob Knight, a professor of pediatrics at the University of California, a microorganism researcher, Follow Your Gut. The Enormous Impact of Tiny Microbes.
Microbes of our body
An average adult carries about 1.5 kg of germs. Great news for those who again did not like the figure on the scales. You can safely minus the "share" of microorganisms. “Each of us has about 20,000 human genes, but at the same time, we are carriers of about 2 to 20 million microbial genes. That is, from the point of view of genetics, we are at least 99% microbes, ”says Rob Knight.
The organisms that live inside and outside of us are numerous and diverse. Most of them are unicellular organisms. They make up all 3 main branches of the tree of life. In your gut you can find representatives of archaea – single-celled organisms that do not have nuclei. They exist without oxygen, help in the digestion of food and emit methane gas. Then come eukaryotes, such as fungi of the mycosis of the legs and yeast, which colonize the genitals. Bacteria predominate in the intestines, such as E. coli. Usually we associate it with a disease that can be picked up if you do not thoroughly wash the vegetables or fruits. However, harmless species of this bacterium live inside most people.
Let us consider more specifically where which microorganisms live and feel good.
Place of registration
Even if you rub yourself with all the antiperspirants in the world, a smell will still come from a person. This is because the microbes that live on the skin feed on our secretions, which enhances the unpleasant odor. Because of them, mosquitoes bite a person. But for some reason, someone more, and someone less. The fact is that microbes turn the chemicals that our skin produces into various volatile organic compounds that mosquitoes like or, conversely, don't like. Scientists argue that the microbes that settle on the skin do not harm us, but rather protect them from more evil and harmful ones. Another interesting fact: more diverse microbial communities live on the hands of women than on the hands of men, and this difference persists even after washing hands. Why – it was not possible to find out yet.
We move to the nose. Staphylococcus aureus is “registered” here, which can cause a lot of trouble, but other neighbors interfere with it. Someone lives in the throat too. But here has its own “party”, its composition also depends on whether you smoke or not. Next is the mouth. A haven for bacteria that cause gum disease and tooth decay. But there are decent microorganisms. Some of them help regulate blood pressure by relaxing arteries with the help of a chemical compound they synthesized called nitric oxide. We approach the main concentration of microbes in the human body – the intestines. Inhabiting the entire digestive system, intestinal germs are the guards of our metabolism. It is they who determine what we can eat, how many calories we absorb, the effects of which nutrients and toxins we experience, how drugs affect us. Here it is!
From the above it becomes clear that microbes not only live in our body and even bring benefits, but also lead to the emergence of diseases that, at first glance, are completely unrelated to them. For example, allergies and asthma.
Do you know why modern European children are so prone to allergies? The fault is the sterility that their parents follow. Scientists have proved that immunity, without receiving material for fighting in the form of microbes, becomes lazy. This leads to the development of allergic reactions and the occurrence of asthma.
About excess weight. Rob Knight writes that studies are being conducted on the effect of microbiome composition on human weight, but there is still no definitive answer. For example, “some changes in diet can cause rapid changes in our germs. Harvard University biologist Peter Thornbo, along with his colleagues, selected courageous volunteers, some of whom switched to a vegan diet, while others consumed only meat and cheese. Veganism almost did not cause instant changes in the microbial composition of the intestines of volunteers. However, the meat and cheese diet caused serious changes the very next day, causing the growth of those bacteria that are associated with the development of cardiovascular diseases. ” Draw conclusions.
How microbes affect our mood
In our intestines, microbes not only affect the digestion process, the absorption of drugs and the production of hormones. They can also interact with our immune system, thus acting on our brain. For example, today it is known that depression is accompanied by an inflammatory process. Many beneficial bacteria in the intestines produce short chain fatty acids, such as biturate, which help nourish the intestinal mucosa cells and thereby reduce inflammation.
The relationship between the microbiome and human depression has been established recently thanks to the discovery that Oscillibacter bacteria produce a chemical that reduces the nervous activity of the brain and can lead to depression. Moreover, taking into account all the influence that microbes have on chemical processes in our body, they, obviously, can determine our consciousness in the process of human development. Of particular interest in this regard is autism. According to some studies, the intestinal microbiomes of autistic children are different from the microbiome of neurotypic children.
These stories can be continued and continued, but it is better to read a book to plunge into the unique world of microorganisms.
Listen to your organism