‘Missing Microbes’: How Hard Should You Resist Antibiotics? And Why

(Photo: R. Zimmerman)

(Photo: R. Zimmerman)

The new book “Missing Microbes” posits that our rampant overuse of antibiotics is not just creating antibiotic-resistant “superbugs”; it is contributing to many of our modern maladies, particularly those affecting children: asthma, allergies, diabetes, obesity.

It’s an idea that has lately been gaining attention and adherents. But you’re especially likely to pay attention and be persuaded when you’re hearing about it from a leading authority on the microbial “ecologies” in our bodies that are damaged by antibiotics: Dr. Martin Blaser, director of the Human Microbiome Program at New York University. Dr. Blaser, who wrote “Missing Microbes,” is in town for a microbiology conference and will be on Radio Boston this afternoon. Our conversation, lightly edited:

As you write, antibiotics are prescribed at incredibly high rates in this country. That’s the big picture, and it’s clear that it’s a problem, but what’s the pragmatic translation? The small picture is something more like a baby who’s been screaming for days and a scared parent who needs to know, just how hard should we resist antibiotics, and in what situations?

We’re starting with perhaps the most difficult question. But you see, in the United States, in order to get antibiotics, you need a prescription. And that means it’s really up to the doctor. And because everyone has thought that antibiotics are ‘free,’ there has been a tendency by both doctors and parents to over-prescribe them and to over-want them. But once you start assigning a cost to them, then the situation changes. And so for parents, I advise them that when their child is sufficiently sick, that they should seek medical attention, and they should try to ensure that the doctor — and that’s shorthand for doctor, nurse, nurse practitioner, physician’s assistant — that the doctor do a careful exam. And then if the doctor says your child does not need an antibiotic, that parent should be relieved. Not thinking, ‘Why is my child deprived?’

But isn’t it so often unclear whether antibiotics are actually needed?

It is unclear, and in fact we know that most of the upper respiratory and ear infections that children have are caused by viruses that don’t even respond to antibiotics. As I write in my book, in the U.S. in 2010, there were 258 million courses of antibiotics prescribed. That’s five courses for every six people. So point number one is that that’s a lot. Point number two is that there’s enormous regional variation — variation that cannot be explained based on variation in the prevalence of different bacterial infections. So that means that it’s a function of how medicine is practiced. And the practice of medicine involves both the doctors and the patients. Both are parties. And what I point out is that in Sweden, where the people are at least as healthy as we are, at every age they’re using 40 percent of the antibiotics that we’re using. And that means, across the board, that 60 percent of the antibiotics are unnecessary. And that’s at every age, not just in childhood –though it’s especially important in childhood at every age. Continue reading