What it is
Sweet proteins from West African fruits, thousands of times sweeter than sugar by weight, used in microscopic amounts to sweeten and mask bitterness.
Why your biology objects
Unlike the synthetics, these are proteins — your gut digests them to amino acids like any other, so there's no foreign molecule lingering and no calories at the doses used. Thaumatin has a long, clean safety record. The lasting cost is the same taste recalibration every intense sweetener trains.