Did you know that we have ten times more microbes in our bodies than human cells?  It may sound gross, but these microbes are often more friend than foe and keep us healthy  in return for a little space to call their own.

There was a fantastic article in yesterday’s Science Times about microbiomes- what scientists call the collection of microorganisms colonizing our bodies.  The study of microbiomes has intensified in recent years and scientists are trying to catalog some of the bacteria we carry.

I eat yogurt filled with healthy, or beneficial, bacteria on a daily basis to keep a healthy population of these little helpers living in my gut.  This keeps the bad bacteria from finding a place to take hold.  A more extreme version of this was mentioned in the Science Times article, where a woman dying of an intestinal infection caused by pathogenic, or bad bacteria was saved when bacteria from her husband’s intestines was introduced into her large intestine.  Within hours, the good bacteria had “kicked” the bad bacteria out, taking over residence.

I also learned that babies born by C-section (like my three kids) are more prone to skin infections and asthma, possibly due to the fact that coming from the sterile amniotic sac, they are colonized by bacteria from adults’ skin rather than that bacteria from their mother’s birth canal.  In fact, people with asthma have a different set of lung microbes than healthy people and obese people have a different set of bacteria in their guts than people of normal weight.

You’ve heard that kids on farms and are exposed to dirt have healthier immune systems than city kids?  It’s not the dirt itself, but the microbes in the dirt giving them their immune systems a boost.

There are years of hard work in the lab ahead of scientists to validate their beliefs that beneficial bacteria may one day be a weapon in the arsenal against infectious disease, but in the meantime, I plan to keep eating my yogurt and letting my kids play in the dirt.

When I told my husband that scientists at the J.Craig Venter Institute had assembled a funtioning bacterium from bottles of chemicals, he said exactly what I was thinking.  “It’s like The Stand.”  Even if you’re not a Stephen King fan, you’ve probably heard of his novel where a genetically engineered strain of the flu virus wipes out almost every human on earth.

USA Today, on the other hand, said “The long-anticipated advance, reported in the journal Science, is a $40 million milestone in the nascent field of “synthetic biology” and points towards a future of designer microbes manufacturing fuels, chemicals and materials.”

The news that a synthetic bacterium has been created comes as no surprise to most scientists.  Even when I worked in a lab ten years ago, we cut and pasted bacterial DNA together on a regular basis.  We also synthesized  relatively short pieces of DNA by pushing buttons on a machine.  The technology has vastly improved since then, and entire bacterial genomes have been sequenced.  Scientists know exactly what it takes to make a functioning bacterial cell.

Some good and bad uses for synthetic biology immediately spring to mind:

Good things:  Scientists may be able to design bacteria that specifically target certain areas of the human bodies, so that the bacteria could colonize those areas (say, the intestine) and produce and deliver drugs to specific organs without causing harm.  You could even turn drug delivery on and off by putting “inducible promoters” which are basically on/off switches, in front of the genes for drug production.  You could possibly use the technology to deliver chemotherapy directly to tumors too, if you could create bacteria that recognize and bind to certain proteins produced by tumor cells.

Bad, bad things:  Bioweapons.  Scientists could potentially piece together nasty bacterial bioweapons that could survive sunlight and even radiation. (Most natural bacteria are relatively fragile and difficult to “disperse” or spread through the air.)

Nature has some controls of her own.  Bacteria must contain certain elements to survive and replicate, and sometimes putting foreign DNA into a bacterium will kill it.  There are also size limits.

We can only hope that the good that comes from this technological breakthrough outweighs the bad.  Later today, I’m planning to pre-order tickets for an amusement park where you’ll be able to see real live dinosaurs in about 20 years.

First of all, I have nothing against real ground beef.  That is, I will eat beef that has been ground by my local butcher or trusted grocer.  I love a good burger.

However, starting today, I refuse to eat ground beef from an unknown source (i.e. fast food restaurants and big chain grocery stores.)  Not only does the ground beef industry refuse to allow retesting of their meat  (they won’t even sell it to stores who retest it,) I just read that one company is taking parts of cow that are considered unusable, treating the beef  ”trash” with ammonia gas to kill harmful bacteria that tend to contaminate those cow parts, and selling it to be mixed with higher quality ground beef to make it cheaper for restaurants and schools (yes, schools!)  This disgusting meat product, which doesn’t list ammonia as an ingredient, although it remains following treatment, may still harbor dangerous bacteria.  It’s unbelievable.

I’m not touching ground beef from an unknown source or letting my kids eat it until the beef industry and the U.S.D.A get their act together.  I’d suggest you do the same.  Maybe if we all boycott their substandard, potentially dangerous product, they’ll stop trying trying to feed us beef products that used to be made into dog food.

For a more complete story, read today’s New York Times article at http://www.nytimes.com/2009/12/31/us/31meat.html?_r=1&hp