This short video explores a thought experiment of what the world would be like without any microbes.

Living without stomach bugs, ear infections, and moldy shower curtains sounds great! But living in a world where all microbes have suddenly disappeared would have a lot of negative consequences. We wouldn’t be able to digest our food properly without our gut bacteria. Crops around the world would start to die without the nutrients generated by microbes. Dead fish would float to the surface of lakes and oceans, and ocean life would be extinguished. The video guides us through this thought experiment to illustrate the many roles microbes play in the world as we know it.

This video is part of the series I Contain Multitudes, hosted by science journalist Ed Yong.