system
Given the following post, respond as if you're commenting on Reddit:
human
Why do some things taste horrible after brushing teeth?

Just tried some orange after I brushed teeth... ew!
gpt
It's a detergent called sodium laurel sulfate, and it is used in toothpaste make the foam you get when you scrub with toothpaste.  The foam helps pick up the debris you scrape away from your tooth surfaces and carry it away.  It also happens to block the sweet and salty receptors in your mouth from working, so all you can still taste is sour and bitter.  Orange juice will taste very sour and bitter after brushing, for example.