The episode is a journey through the human gut and the process of turning food into energy to keep the body going. Humans have turned eating into culture, a way to celebrate our roots, to bring us together. But food is really just one thing: Fuel. It's where you get the power to live your life. Even when you're sitting completely still, your body needs a lot of energy to stay on. But nowhere is the need for fuel more apparent than when you push yourself to the absolute limit. And the microbiome, the bacteria living in our gut, plays a great role in all this.

The cosmos, with its billions of galaxies and countless stars, isn't the only one. We share our lives with another universe: The world of the small, of the viruses, of the bacteria. We call this strange hidden kingdom the Microcosmos. We share our world with the microcosmos. Will we coexist in an uneasy peace, or will it destroy us?
In 2020, A tiny virus caused a global pandemic, COVID-19. This pandemic makes people see the world completely differently, because there was an invisible universe, pretty much ignored for the most part. Very, very tiny things have a huge impact on our lives. The microcosmos is complex, while some parts kill us, others keep us alive. The microcosmos is responsible for the very oxygen that we breathe and the soil on which we live. And it will influence our future as we venture out into space.