That’s because we are mostly bacteria. In a census of every single cell in our bodies, roughly 9 in 10 of them would turn out to be bacteria. Scientists refer to this as the “microbiome.’’ We are an environment that plays host to microorganisms. Each of us is a world.
It has been known for some time that we depend on this world. Vitamin K, which we rely on for survival, is synthesized by bacteria in our gut. More recently, though, it has become clear that many other bugs are likely good tenants.
“It is not a simple story like bug equals bad,’’ says Dr. Martin Blaser, chair of the Department of Medicine at New York University’s Langone Medical Center. Blaser argues that a long list of serious conditions - among them obesity, asthma, allergies, type 1 diabetes, and inflammatory bowel disease - may be linked to our increased use of antibiotics, and the changes it is causing in our microbiomes.
Blaser first became interested in the topic some three decades ago. In the early 1980s, a pair of Australian scientists proposed that a bacteria called H. pylori in the stomach was responsible for ulcers. It was a strange notion. Ulcers were thought to be a side effect of stress. But the strange notion proved to be fact, and it earned the pair a 2005 Nobel Prize.
H. pylori is common, and this prompted Blaser to wonder what else the H. pylori might be doing in the body. So he looked a bit north, at the esophagus. There he found a link between H. pylori and reflux disease as well as a form of esophageal cancer. But the link was not what you might expect: Those who had the bug were more likely to be healthy, not sick.
From there, Blaser made another leap, to asthma. Again he has shown that people who have H. pylori are less likely to suffer from asthma.
Admittedly, this sounds a bit loony. What could bacteria in the stomach possibly have to do with asthma?
