More than 10 000 species of germs live in and on people

“When I get up from the chair 10 times more bacterial cells than human ones stand up with me” says Dr Bruce Birren, who participates in creating one of the most accurate maps of microbes that live in and on us. 

Human’s Microbiome project launched in 2007 by the USA, determined genetic identity of many bacterium, viruses and other microorganisms that live in a close contact with us.

Researchers say that it is not about naughty germs, that should be eliminated, but about microorganisms as an integral part of our human bodies. 

Nevertheless, until lately nothing was known about trillions of microbes on our body.

For centuries we could explore only organisms that can survive in the laboratories and investigate them in isolation – often one at a time. But with an advent of more perfect DNA analysis methods, the researchers of Human’s Microbiome Project could detect microbes never seen before, and look at their collective behavior. 

The results of five years work started by the US National Institute of Health were published in the magazines. 

Within this project over 200 healthy men and women in the USA had microbe samples taken from different parts of their bodies.

The researchers found that the healthy human microbinome is inahabited by over 10 thousand of different microorganisms.  

Most of these microbes turned out to be harmless at all. There are even proofs that these organisms help us in many ways. 

Some of them help us to get energy from the food, while the others help us to absorb such nutrients as vitamins.

“We are learning more about their role in forming out immune system rather than just attacking it” says Prof Barbara Methe from the J Creig Venter institute, also involved in the project.  

One of the key points the researchers tried to learn of microbe maps - is there a core set of microbes that all humans share? 

Scientists found out the variety of protozoa across different people and unique comminities of germs living on different parts of body. 

But some of microbiologists were really surprised that microbes on particular parts of body shared similar processes.

“Different organisms can live on our tongues, but together they contribute the same genes and help to perform the same functions,- for example, breaking down sugar.” – Bruce Birren explains.

These findings suggest the shift thing about the model of “one microbe-one disease” that places responsibility for disease on the one germ. “On occurrence of some diseases what really matters is a functioning of group of microbes, but it isn’t a particular bug” – supposes Dr. Curtis Huttenhower from the Harvard School of Public Health. 

Researchers found that healthy volunteers carry a small number of microbes that are considered to be pathogenic.

For example, a bacteria methicillin – a resistant Staphylococcus aureus the infection MRSA and bilateral pneumonia was found in the noses of nearly 30% of participants.

“Now we have a “phone book” of more than 100 similar germs that under certain circumstances can go bad. We know where they live in healthy humans and which organisms surround them. So perhaps, we may probably start to understand what deters them and where their reservoirs are.” – says Dr. Huttenhower.

“Microbes carry many genes. These genes have the same ability to influence our health and diseases, as much as our own. –assures Curtis Huttenhower. 

A program director of the project Lita Proctor and her colleagues incline to a conclusion that we choose our microbinomes at the very beginning of our life.

“The human’s genome is inherited, but microbinome is acquired – it means that it is very prone to changes and mutations. We are working on this in the clinical settings. If you can manage microbinome, you will be able to preserve it healthy and change its unhealthy balance”- explains Proctor. 

According to Proffessor David Relman from the Stanford University, these studies is just half story, because we have to know much more about the “dialogue” of microbes with human’s cells. 

“It is still a “terra incognita”. Even in familiar environment we are still discovering new life forms.”- says Relman.