The human microbiome
Scientists will read the genes of human bacteria
Alexey Tymoshenko, GZT.RUAccording to preliminary estimates of scientists from the USA, the number of microbes can exceed the number of cells of the human body by 10 times.
In order to study the most important types of bacteria living in humans and read their genome, the Human Microbiome program was launched. Scientists from the American Institutes of Health (NIH) expect to read the genome of 400 species of bacteria. $115 million has already been allocated for the implementation of this project by 2011.
What for?
Microbiologists believe that most microorganisms living in the human body are harmless. Some are absolutely necessary for a healthy life. But another relatively small part of the bacteria causes various diseases – from teenage acne to stomach ulcers. Moreover, unlike the causative agent of plague or anthrax, these bacteria live in a healthy body, leading to the development of the disease only under unfavorable circumstances.
To understand what these circumstances may be and how to prevent the development of diseases caused by microbes constantly living with humans, scientists will fully read the genome of 400 bacterial species out of about 2000.
Where?
As Brett Finlay, a microbiologist at the University of British Columbia in Vancouver, says, a person can be called a "superorganism" in which no more than 10% of human cells are actually human. Everything else is bacteria that live on the surface of the skin, in the intestines and vagina. However, these 90% are still in quantity, not in mass. In other words, the number of bacteria is 10 times greater, but their mass (due to their smaller size) is much smaller.
The sterile intestines of a newborn are populated by many different bacteria, and a real ecosystem is formed in it: a certain balance is maintained between the number of different microorganisms, and for each person - its own. The intestinal microflora plays an important role in the processing of food eaten, and the previously considered useless appendix, as a recent study has shown, also serves as a refuge for bacteria.
Another study, the results of which will already be actively used in the Human Microbiome project, was devoted to the skin. Then biologists and doctors from the same National Institute of Health in the USA studied the microflora of the skin. They found that most of the known types of bacteria live on the skin and even made a map showing their distribution. Now this map will be used to select the most important types of microorganisms that can most affect human health.
Probiotics The message that American doctors and scientists have already begun a detailed study of bacteria living in humans would be incomplete without comparison with another piece of news.
In the latest issue of the journal Archives of Pediatric and Adolescent Medicine, an article was published by doctors from the United States who checked whether kefir really helps to cope with intestinal disorders after taking antibiotics.
As it turned out during the observation of 125 children in two different hospitals, the probability of developing diarrhea after antibiotic therapy does not depend on kefir consumption. And in an even earlier study by Danish doctors (from 2004 to 2007), it was also shown that probiotics are even dangerous for pancreatitis – among the patients who took them, the number of deaths was noticeably higher. By the way, there is no diagnosis of "dysbiosis" in the international classifier of diseases, for example, very popular among manufacturers of dietary supplements and fermented milk products.
Which, of course, does not negate the importance of bacteria living inside a person, but indicates that their role, composition and "habits" require further detailed study. By 2011, perhaps, there will be more certainty in the question of beneficial, neutral and harmful bacteria.
Portal "Eternal youth" http://vechnayamolodost.ru04.09.2009