They’re small and invisible, but they can cause big things inside and outside of us. Bacteria are everywhere, on our skin, in our intestines and in the atmospheric environment. Knowing them helps us to understand their behavior: that’s why a new and definitive census has been made and has finally classified them all. Up to now, only 23 percent of species had been recorded. Today, however, we know that there are 154,000 types in all, divided into 5,000 species. We talked about the work carried out by the University of Trento and told by the magazine “Cell” with Dr. Marta Monari, of the laboratory of analysis of Humanitas.

Bacteria are essential to life

Where there’s life, there’s bacteria. These microorganisms, that were formed 4 billion years ago, colonized the Earth until the appearance of the human species. The last census counted 150,000, divided into 5,000 species. The work presented in the magazine Cell has been completed by the University of Trento, where with a research of computational metagenomics coordinated by Nicola Segata and Edoardo Pasolli of the Laboratory of metagenomics have put together the book of bacteria that live in our body more complete and extensive so far never realized.

This has also made it possible to make the identikit of the entire human genome, variable in age, subject and health conditions. Today it is estimated that the number of bacteria present in our body reaches 40 thousand billion.

Bacteria are everywhere

“Until now, 23% of the species has been recorded,” explain the researchers. Our work has brought to describe and analyze the remaining 77 percent that was unknown. But there are several who live in symbiosis with others which made the operation very difficult. That’s why we decided to collect and study directly 9428 samples taken from all continents.

The microbiome in fact is affected by variations depending on the location of the Earth in which you are located. In western countries, for example, is different than the national non-westernized.

“We have lost bacteria that still live in non-Westernized populations and this is the consequence of our different lifestyle, nutrition, industrialization, use of antibiotics and hygiene,” explained the experts – “Our work is the result of a massive effort that has combined computer skills and ability to handle huge amounts of data. We have come to an important conclusion: creating the conditions to be able to study the various species of bacteria now with a precise objective regarding our health”.