In the human body, thousands of unknown microbes

Genetics from Harvard decrypted the DNA of microbes living in the human microflora and discovered thousands of new strains of bacteria and fungi that scientists had not previously suspected existed, according to an article published in the journal Nature.

“When we decoded the human genome for the first time, having no idea how much the structure of individual genes changes and under what conditions they work, we could not immediately understand how this information can be used to find medicines and diagnose diseases. the same thing awaits us – we still have much to study so that the secrets of microflora can be used for the benefit of man, “said Jason Lloyd-Pierce, a Harvard geneticist and a member of the Human Microbiome Project.

The human body contains about 10 times more unicellular bacteria, fungi and other microflora than our own cells. Observations of recent years show that microflora can not only affect human metabolism and the likelihood of cancer and other diseases, but also its behavior.

For example, a year ago, American biologists discovered, experimenting in mice, that the development of autism may be due to the lack of one type of microbes, the bacteria Lactobasillus reuteri in the intestines of children and their mothers.

In addition, Russian biologists have repeatedly suggested that microflora can affect more complex behavioral reactions, affecting the level of hormones and signaling molecules of the nervous system. More recently, scientists have discovered hints that the features of the device and brain function in women can be related to the structure of their microflora.

The search for such links between the work of microflora, health and human behavior, according to Lloyd-Pierce, is hampered by the fact that we know almost nothing about exactly what microbes inhabit the intestine and other human organs. Ten years ago, the National Institutes of Health of the United States launched the Human Microbiome Project initiative, in which scientists conduct a full “census” of the population among representatives of microflora.

Lloyd-Pierce and his colleagues analyzed the structure of DNA and isolated about two thousand species of bacteria, archaea and other microflora inhabitants, whose existence genetics had not previously known, and also analyzed their possible role and function in the body’s work.

As the scientists note, they managed to prepare a preliminary version of the “map” for the distribution of microbes throughout the body, and to monitor how their species composition changes as the person grows up or grows older. In addition, scientists have revealed several new interesting links between metabolism and the composition of microflora – for example, in the intestines of full people, there are more microbes that produce methane than in the body of lean people.

In addition to bacteria and archeas, scientists have found dozens of previously unknown viruses in samples of the microflora of people that do not affect human cells, but many pathogenic bacteria. For example, in the saliva there are several viruses that destroy streptococci and other carious bacteria, and the intestine is inhabited by bacteriophages that destroy dangerous varieties of lactococci.

All these data and subsequent stages of the Human Microbiome Project, as scientists hope, will help us understand how the microflora affects human health and behavior, and will give us a chance to learn how to manage it.