The microbiome in it, exactly.

We are meat suits driven by primitive bacteria. Explains a lot, me thinks.

You've gotta be shitting me.

And the fact that the heart has nothing to do with emotions. The brain doesn't even get to be represented in the comic!

Possibly that even is the joke :P

We even acknowledge it:

"I have a gut feeling he's the murderer"

"Waking up to learn Hillary had lost was a gut punch"

"I feel a visceral anger every time I hear his smug and smarmy voice, even before I'm disgusted by what he says."

I've suspected this, but source?

Edit: Oh, metabolomics

Nevertheless you can die of heartbreak 💔

I know this even without the research. I have IBS, and my modd can change on a dime at the same time my gut changes moods. Like, if I get gas, or indigestion, it can be quite sudden. And at the same time my entire demeanor will flip like a switch. Sometimes before I feel it in my gut. Like I can be asking myself why am I so depressed and then the guy bomb will hit and I'm like oh, that's why.

Like 80% of the serotonin in your body is in your intestines iirc.

And what should I eat to become angry like Hulk?

This comment is great out-of-context.

And the vacant eyes