Cutting-edge techniques and cost-effective methods of rapidly sequencing entire genomes of bacteria and viruses are transforming the field of microbiology. With these tools, a new generation of microbe hunters has launched a number of fascinating projects, including efforts to determine the origin of specific diseases and to produce Doppler radar-like maps depicting the prevalence of pathogens in specific locations.
In an article in today’s New York Times, Stanford professor of microbiology and immunology David Relman, MD, commented on the tremendous impact these technological changes have had on researchers. He said, “We are able to look at the master blueprint of a microbe… it’s like being given the operating manual for your car after you have been trying to trouble-shoot a problem with it for some time.”
The story gives an overview of how investigators are employing so-called “molecular forensics” in the lab as well as clinical settings, and it highlights work by Relman to better understand how the sea of microbes that live in and on our bodies influence our health:
There are far more bacterial genes than human genes in the body, [Relman] notes. One study that looked at stool samples from 124 healthy Europeans found an average of 536,122 unique genes in each sample, and 99.1 percent were from bacteria.
But if these vast communities of microbes are as important as researchers think they are for maintaining health, Dr. Relman asked, what happens when people take antibiotics? Do the microbial communities that were in the gut recover?
Using rapid genome sequencing of all the microbes in fecal samples, he found that they did return, but that the microbial community was not exactly as it was before antibiotics disturbed it. And if a person takes the same antibiotic a second time, as late as six months after the first dose, the microbes take longer to come back and the community is deranged even more.
Now he and his colleagues are looking at babies, taking skin, saliva and tooth swabs at birth and during the first two years of life, a time when the structure of the microbe communities in the body is being established.
“We wait for the babies to be exposed to antibiotics — it doesn’t take that long,” Dr. Relman said. The goal, he says, is to assess the effects on the babies’ microbes, especially when babies get repeated doses of antibiotics that are not really necessary.
Previously: Study shows intestinal microbes may fall into three distinct categories, The future of probiotics, Study offers new insights into link between oral hygiene and heart health and Your bacterial birthday suit reveals the mode of your birth
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