system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do antibiotics work?

How exactly do antibiotics work?
gpt
Pretend your cells and the cells of everything living are made from Lego. Bacteria have some of the same pieces of Lego in their cells as humans do, but also have some Lego pieces that are very specific to bacteria and are not found in humans. Most antibiotics work to target those Lego pieces that exist in bacteria, but do not exist in human cells. This way they can selectively target bacteria and hopefully human cells will not be affected.