Trust Your Gut

Antibiotics Quick: What do you say when someone tells you that your entire body is covered in bacteria?

A) “Yuck!”

or

B) “Yay!”

If your answer was A, you’re not alone, but your gut would certainly disagree.

That’s because, as Martin J. Blaser, M.D., describes in his new book, Missing Microbes, the bacteria that coat your skin, inhabit your mouth, and fill your intestines are essential to your health and well-being. They protect you from harmful pathogens, help digest your food, produce vitamins, and fine-tune your immune system.

Unfortunately, Blaser explains, we have not been giving these essential partners the respect they deserve. For the past 75 years we’ve been bombarding them with antibiotics without realizing that when we were shooting at the bad guys, we were also hurting the good guys. And the rising incidence of chronic conditions from obesity to asthma to allergies may be the price we are paying.

The trillions of microbes that make their home on the human body — known as the human microbiome — are not a random collection of bacterial passersby. Instead, the particular kinds of bacteria, the sites of the body they occupy, and the functions they carry out are the result of hundreds of thousands of years of evolutionary selection. All the life forms we see around us — plants, insects, mushrooms, fish, mammals — evolved on a planet where life was entirely microbial for billions of years. We may think of evolution as a process of “higher” life forms leaving these “primitive” organisms behind, but in fact, every multicellular organism has a group of microbial partners that provide it with various selective advantages. There are a million wonderful stories to tell about these microbial partnerships, but Blaser’s book focuses on the one between humans and our microbiome, and the unintended consequences of one of humanity’s greatest inventions: antibiotics.

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