system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If the gut biome is responsible for extracting nutrients from food that we can't extract naturally, how do we receive said nutrients from the bacteria?
gpt
Much of it is through the microbes’ waste. This may sound gross but keep in mind these simple microbes are often just taking some nutrient and only slightly processing it because that’s all they’re equipped to do.  
Like, imagine if you swallowed an apple, and pooped out a peeled apple.