This is a high level article. The gut is a catch all term for both intestines and the microbiome (the fancy technical word for poop-snake). The intestines are responsible for nutrient transmission into the blood, and recovering water and water soluble nutrient from the poop-snake.

The poop-snake does most of the heavy lifting.

The bacterial and viral flora, fauna, and virol-bing-banna are responsible for processing vitamins, minerals, producing hormones, and a incomplete list of other necessary compounds and proteins that one cannot even begin to be listed, as they have barely scratched the surface of what it does; let alone how it works.

The poop-snake tells the brain:

• What to food you like
• What types of food too crave.
• When to take action (#2 were looking at you).
• A whole buncha other shit that I have no idea about, cause no one in all of human history does either
  

A large portion of who and what you are is directly determined by the poop-snake.

Most people treat the poop-snake like shit, but it really deserves a hug. You should learn to love it.

Does anyone think I'm making all of this up? Feel free to fact check me. >:-}.

This post was an attempt to generously cover every inch of the pyramid of debate. How'd I do? I'm interested in feedback. Thanks! ;-)