Your body is not your own. The bacterial cells seeking safe harbor inside your gastrointestinal tract outnumber your actual cells by a factor of 10. According to the NIH, the genes encoded by the bacterial carpetbaggers outnumber your own genes by more than 100 times.
But that's no reason to fear them. We're in a symbiotic relationship with creatures, just like whales who get their teeth cleaned by tiny fish. For the most part, anyway. YouTube channel Kurzgesagt takes a look at the hot-cold relationship we've got with our gut bacteria.
The gut bacteria are pretty active participants in your day-to-day life, even if you're unaware. Interacting with your neural pathways, they might be able to influence neurobehavioral changes ranging from depression to eating patterns.
The gut has a complexity that science is still trying to understand. But historically, they've been our allies as much as our enemies. The more we learn about them, the more we'll be able to further our symbiotic relationship along and make them work for us.
David Grossman is a staff writer for PopularMechanics.com. He's previously written for The Verge, Rolling Stone, The New Republic and several other publications. He's based out of Brooklyn.
