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.
For centuries, people have harvested corn by hacking it off, six to fifteen inches above the ground. A caterpillar called the corn borer appears to have adapted its behavior to the corn harvest by travelling back down the stalk to a safe height, before spinning its cocoon. This week, the Science Times reported on a study that suggests that, by descending to the bottom of the stalks, the bugs avoid being chopped off when the corn is harvested. Researchers at McGill University think that “over generations, those caterpillars that did not descend, or did not go down far enough, did not survive.” In the article, Dr. Calcagno suggests that the likeliest explanation for this behavior is the selection pressure of harvesting over generations. In other words, only the caterpillars that crawled down survived to reproduce and make baby bugs, until only caterpillars with the family trait of crawling down remained in the population.
Similar forces are at work on bacteria that live in animals and humans, only instead adapting to harvest, they’re adapting to constant exposure to antibiotics. As a result, many harmful bacteria are finding ways to “outsmart” antibiotics. This is, in part, due to the mind-boggling volume of these drugs fed to animals produced for food. I can’t give you a number, because according to the Center for Disease Control’s website, the amount of antibiotics fed to farm animals is not available to the public or to government agencies.
Feeding animals antibiotics helps them grow. No one knows exactly why. Unfortunately, using these drugs as growth enhancers, or even to protect them from disease, often creates antibiotic-resistant strains of bacteria that have the potential to end up in our food supply. These drug-resistant pathogens are especially dangerous to people who live and work on farms ( just ask Russ Kremer, who was gored by one of his hogs and nearly died from an antibiotic-resistant infection.) In reponse to the global threat presented by antibiotic resistance, the World Health Organization recommended that antibiotics used in humans should not be used to promote growth in food animals.
Healthy animals occasionally need to be treated for infections, but feeding animals antibiotics for growth benefits is a risk no one should be taking. A huge amount of money is spent each year on these drugs so producers can get top dollar for their animals. My worry is that the additional costs to public health are not being considered, especially if our pharmaceutical arsenal is rendered useless by this practice.
I found lots of interesting tidbits in today’s Science Times!
In science news, my son was fascinated to learn that ABE, a pioneering undersea robotic explorer, appears to have implodedunder about 10,000 feet of water while searching for hydrothermal vents in the sea of southern Chile. We also read that “Fearless Felix” Baumgartner is going to jump from a helium balloon in the stratosphere, 120,000 feet above earth in an attempt to be the first skydiver to break the speed of sound.
In health news, The Science Times today tells us that a study showed that when soda prices went up, consumers health improved. (Not that surprising, really.) There was an interesting article about new research showing that taking an anti-inflammatory related to aspirin helped Type 2 diabetes patients manage their disease and even lower their blood sugar. This seems to be further evidence that inflammation plays a role in diabetes. There is also a good article about Dr. Thomas Frieden,the new director of the Centers for Disease Control and Prevention in Alanta. I was happy to read that he’s reorganizing the agency to give scientists better access to top leadership and popping into research labs on a regular basis to see what’s going on.