• The Good: Accessible but thoroughly researched pop science about bacteria!
  • The Bad: Some reaching conclusions about autoimmune diseases based on preliminary studies
  • The Literary: Extensive bibliography

Every mammal, every animal, including humans, is host to millions of bacteria and other microbes. Some bacteria makes us sick, but we also take probiotics, and in fact, most bacteria are not only beneficial, but necessary to life. They build our bodies, make up our immune system, and even shape our identities.

This book is a treasure trove of fun party facts, so let me share a few. In cows and termites, their gut bacteria literally digest the plants they eat. The bacteria that make it possible for koalas to leach as much nutrition as they do from eucalyptus is passed from mother to infant while the infant clutches to its mother’s back as they ride through the forest. Tubular creatures in the deep ocean who have no mouth or guts subsist entirely on microbes to live. You’ll also learn why the coral reefs are dying and how the flu adapts so quickly.

All these interesting tidbits lead to the conclusion that none of us is actually a single organism. If you were to erase all microbes from your body, you’d surely die. In fact, if you were to count all your human cells and all your microbial cells, you’d come up with roughly the same number. Think of that—each of us is half human, half bacteria. Of course, human cells are a lot bigger and weigh a lot more than bacterial cells, and most of those bacterial cells are in our gut, but it’s still amazing. We are an interconnected, interdependent collection of beings that need each other to survive. We are multitudes. We’ve evolved together and are connected to the world around us in ways we cannot see.

So, what do we do with this new knowledge? For one, stop taking antibiotics when you don’t need them. If you’re pregnant and healthy, opt for a natural birth over a c-section so your baby won’t lose out on the richness of all the microbes they naturally obtain when they pass through the birth canal. Also, breast feed—a mother’s milk literally builds her child’s immune system. If you’re past the nursing stage, one easy way to introduce good bacteria to your body is to eat lots of different foods. Also, adopt a dog. But too much bacteria isn’t good either, especially if you’re sick and confined to a room, it’s easy to “stew in your own microbiome juices”.  If possible, go out, or just open a window. Maintaining the ideal microbiome is a balance, and scientists are working towards identifying the host of good bacteria we need to be healthy.

Come revel in the all the fascinating variety, new scientific research, and often yucky world of bacteria!