Tending the Body’s Microbial Garden

Here is an excellent overview of the microbiome, we briefly mentioned in class.

For a century, doctors have waged war against bacteria, using antibiotics as their weapons. But that relationship is changing as scientists become more familiar with the 100 trillion microbes that call us home — collectively known as the microbiome.

No one wants to abandon antibiotics outright. But by nurturing the invisible ecosystem in and on our bodies, doctors may be able to find other ways to fight infectious diseases, and with less harmful side effects. Tending the microbiome may also help in the treatment of disorders that may not seem to have anything to do with bacteria, including obesity and diabetes.

These links are worth investigating to learn more about the Human Microbiome Project (HMP).   Judging from a flood of recent findings about our inner ecosystem, that appears to be happening. Last week, Dr. Segre and about 200 other scientists published the most ambitious survey of the human microbiome yet. The Human Microbiome Project is based on examinations of 242 healthy people tracked over two years. The scientists sequenced the genetic material of bacteria recovered from 15 or more sites on their subjects’ bodies, recovering more than five million genes.   This project and other studies like it are revealing some of the ways in which our invisible residents shape our lives, from birth to death.   Here are some NIH  demonstration projects at the HMP.   

In this article, one interesting study (of many mentioned) is that a baby’s microbiome continues to grow during breast-feeding. In a study of 16 lactating women published last year, Katherine M. Hunt of the University of Idaho and her colleagues reported that the women’s milk had up to 600 species of bacteria, as well as sugars called oligosaccharides that babies cannot digest. The sugars serve to nourish certain beneficial gut bacteria in the infants, the scientists said. The more the good bacteria thrive, the harder it is for harmful species to gain a foothold.   

As the child grows and the microbiome becomes more ecologically complex, it also tutors the immune system, however ecological disruptions can halt this education.  Read more on how experiments on mice reveal how this happens.

Antibiotics kill off harmful bacteria, but broad-spectrum forms [of antibiotics] can kill off many desirable species, too. Antibiotics are likened to herbicides sprayed on a garden. The herbicide kills the unwanted plants, but also kills off the tomatoes and the roses. The gardener assumes that the tomatoes and roses will grow back on their own.   In fact, there’s no guarantee the microbial ecosystem will automatically return to normal.

Please read this article and the links attached to the article (under Related Coverage).   As you do so, let me know what you think.