A deepening understanding of how important bacteria are in our bodies! -
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.
“I would like to lose the language of warfare,” said Julie Segre, a senior investigator at the National Human Genome Research Institute. “It does a disservice to all the bacteria that have co-evolved with us and are maintaining the health of our bodies.”
This new approach to health is known as medical ecology. Rather than conducting indiscriminate slaughter, Dr. Segre and like-minded scientists want to be microbial wildlife managers.
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.
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. Known as the Human Microbiome Project, it 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.
The project and other studies like it are revealing some of the ways in which our invisible residents shape our lives, from birth to death.
A number of recent reports shed light on how mothers promote the health of their children by shaping their microbiomes. In a study published last week in the journal PLoS One, Dr. Kjersti Aagaard-Tillery, an obstetrician at Baylor College of Medicine, and her colleagues described the vaginal microbiome in pregnant women. Before she started the study, Dr. Aagaard-Tillery expected this microbiome to be no different from that of women who weren’t pregnant.
“In fact, what we found is the exact opposite,” she said.
Early in the first trimester of pregnancy, she found, the diversity of vaginal bacteria changes significantly. Abundant species become rare, and vice versa.
One of the dominant species in the vagina of a pregnant woman, it turns out, is Lactobacillus johnsonii. It is usually found in the gut, where it produces enzymes that digest milk. It’s an odd species to find proliferating in the vagina, to say the least. Dr. Aagaard-Tillery speculates that changing conditions in the vagina encourage the bacteria to grow. During delivery, a baby will be coated by Lactobacillus johnsonii and ingest some of it. Dr. Aagaard-Tillery suggests that this inoculation prepares the infant to digest breast milk.
Click Studies of Human Microbiome Yield New Insights – NYTimes.com to read the full article.