Martin Blaser, MD
Henry Holt
By Henry Ehrlich
A couple of weeks ago, when I was half way through the book that has turned Martin Blaser into a media superstar—at least among NPR listeners and fans of “The Daily Show” –an article came up on my Twitter feed that started this way:
Despite clear evidence of ineffectiveness, guidelines and more than 15 years of educational efforts stating that the antibiotic prescribing rate for acute bronchitis should be zero, the rate was about 70 percent from 1996-2010 and increased during this time period.

Don’t we know better, and why haven’t doctors gotten the message? Thus, Dr. Blaser’s timely and compelling book. Unlike other unified field theories of how we became more obese, more allergic, more asthmatic, more autoimmune, and so forth, Dr. Blaser backs his with a long career of passion for the microbiome and the science it has inspired. Part memoir, part family chronicle, part panorama of evolution since the primordial ooze, Microbes is so well written—Dr. Blaser founded the Bellevue Literary Review—that you sometimes forget you ought to be scared to death. In the hands of a writer like Michael Crichton or Robin Cook, and a story arc of seven days instead of seven decades that can be compressed into a two-hour movie, we would have our summer blockbuster. The novel Jaws was published 40 years ago, and the movie will turn 40 next year; think of Dr. Blaser in the role created by Richard Dreyfuss—the scientist no one will listen to.
The Missing Microbes has all the elements—greedy corporate cattle barons, anxious to fatten their livestock; rapacious pharmaceutical executives, looking for new markets for their wonder drugs; arrogant physicians, acting like 19th-century generals and railroad magnates surveying the American continent, practicing medicine as though “the only good h. pylori (helicobacter pylori) is a dead one”; and credulous parents, usually trying to do what’s best for their children’s health and comfort.
Dr. Blaser explains that h.pylori did indeed contribute to ulcers and a certain number of stomach cancers, which won the discoverers a Nobel Prize, but exterminating microbes has disrupted an ecosystem that evolved over millions of years. The trillions of microbes that once inhabited our guts, skin, and airways all had jobs to do—digest certain foods that now contribute to our body mass, fight infections, and most importantly for readers of this website, help us process proteins as harmless or nutritious instead of mobilizing our immune systems to fight. In this, as Dr. Blaser points out repeatedly, doctors have mistaken association for causation and gone after the wrong targets.
“The most popular explanation for the rise in childhood illness is the so-called hygiene hypothesis. The idea is that modern plagues are happening because we have made our world too clean. The result is that our children’s immune systems have become quiescent and are therefore prone to false alarms and friendly fire. A lot of parents these days try to ramp up their kids’ immune systems by exposing them to pets, farm animals, and barnyards or better still by allowing them to eat dirt.
“I beg to differ. To me, such exposures are largely irrelevant to our health.” For Blaser, the microbiomes of dogs and dirt have evolved for dogs and dirt, not people. Micro means micro.
For millions of babies, the problems begin at birth. Cesarean section deprives newborn babies of exposure to the rich microbial environment of the birth canal that sows the seeds of a beneficial biodiversity. For the rest of us, multiple courses of antibiotics in childhood wipe out good bacteria as well as bad. Once they are gone, we will likely never get them back.
Blaser is no paleo enthusiast. He is extraordinarily eloquent in making the case for the miracle antibiotics have wrought in public health, starting with the fact that a century ago two of his father’s sisters died before their second birthdays from high fevers that likely would have been cured by penicillin. He makes the scientific case that there should be single-purpose antibiotics instead of the broad-spectrum Z-pak that many of us have used on our kids (often for symptoms of viruses for which they have no therapeutic value). He also explains the dismal economic case that pits pharma against public health.
What can be done about it? Dr. Blaser is a realist—he says that once these beneficial bacteria are gone, that’s it—but also expresses a highly tempered optimism. Some day probiotics may allow us to restore some of the missing microbes, although he says we have little proof that anything currently on the market has any utility. Fecal transplantation from healthy intestines is very promising, but there remain challenges of science, regulation, and medical custom (“you’re going to put what where?”) to be surmounted. Vaginal gauze may help restore some of what Cesarean birth takes away in cases when the procedure is medically necessary. But we have to break the prescription habit, and we’re nowhere near doing so. Pediatricians are still under relentless parental pressure for bubble-gum medicine–amoxicillin–every time a child has an ear infection.
The trouble with long-term optimism is that the short-term is truly frightening. The same antibiotics that have indiscriminately killed good bacteria while treating (or not treating) disease have allowed resilient bacteria to rise from the crypt. MRSA (methicillin-resistant Staphylococcus aureus) and clostridium difficile infections that evolved in hospitals are resistant to conventional antibiotics and we have no weapons left in the arsenal to treat them. “Whatever doesn’t kill me makes me stronger” applies to microbes, too.
Buy and read Dr. Blaser’s book. Great for the beach. Just when you thought it was safe to go back to the pediatrician…