system
Given the following post, respond as if you're commenting on Reddit:
human
If we created a colony on Mars, could we make it disease free? 

Of communicable diseases, at least.
gpt
No.  We, as humans, need bacteria to survive.  We need natural "helpful" bacteria which live within our digestive tracts, in our airways, and over every millmeter of our skin.

Given time, and the outrageous rate at which bacteria mutates, it is inevitable that some strains of said bacteria would become virulent.