Nice To Meet Your Microbes

The New York Times had an eye-opening science story on July 12, 2010 about the recent research and medical advances in the field of human-dwelling microbes. This story is a perfect example of why I inevitably fall back to science as my reading material of choice. (Yes, my “beach reads” are even books about popular science. I read “Cosmos” by Carl Sagan by the pool in Puerto Vallarta, Mexico. Ah. Heaven.)

The facts in this story prove yet again that, in science at least, truth is often stranger than fiction.

I had heard previously of applying this new microbial science as a potential new forensic tool. (CSI needs something new-they use the same human DNA tests every episode.) In this application, they would utilize the trail of microbes we leave behind as tool for identifying criminals. Think living, microbial fingerprints. Here’s an article about microbe fingerprints. (Bonus, the article is written for kids. Kids need science for their futures, and science needs kids for its future.)

I would not be surprised if the link grows stronger between underexposure to bacteria during childhood (too many antibiotics and not enough dirt) and the occurrence of allergies and asthma.

Here are a few excerpts from the NYT article:

“We have over 10 times more microbes than human cells in our bodies,” said George Weinstock of Washington University in St. Louis.

…

The new surveys are helping scientists understand the many ecosystems our bodies offer microbes. In the mouth alone, Dr. Relman estimates, there are between 500 and 1,000 species. “It hasn’t reached a plateau yet: the more people you look at, the more species you get,” he said. The mouth in turn is divided up into smaller ecosystems, like the tongue, the gums, the teeth. Each tooth-and even each side of each tooth-has a different combination of species.

…

Lungs have traditionally been considered to be sterile because microbiologists have never been able to rear microbes from them. A team of scientists at Imperial College London recently went hunting for DNA instead. Analyzing lung samples from healthy volunteers, they discovered 128 species of bacteria. Every square centimeter of our lungs is home to 2,000 microbes.

…

Out of the 500 to 1,000 species of microbes identified in people’s mouths, for example, only about 100 to 200 live in any one person’s mouth at any given moment. Only 13 percent of the species on two people’s hands are the same. Only 17 percent of the species living on one person’s left hand also live on the right one.

…

In addition to helping us digest, the microbiome helps us in many other ways. The microbes in our nose, for example, make antibiotics that can kill the dangerous pathogens we sniff. Our bodies wait for signals from microbes in order to fully develop. When scientists rear mice without any germ in their bodies, the mice end up with stunted intestines.

…

Caesarean sections have also been linked to an increase in asthma and allergies in children. So have the increased use of antibiotics in the United States and other developed countries. Children who live on farms – where they can get a healthy dose of microbes from the soil – are less prone to getting autoimmune disorders than children who grow up in cities.

via How Microbes Defend and Define Us from NYTimes.com