There is a berry that changes how you taste. Synsepalum dulcificum, commonly called the “miracle fruit,” contains a protein called Miraculin. Miraculin coats the taste buds and changes how receptive the human body is to sour foods—after consuming the berry, foods that normally are sour appear to taste extremely sweet. For fifteen minutes to an hour, no other taste sensations are changed, but all sour foods taste more like sugar. Miraculin is currently being investigated as an alternative sweetener, as it could produce a sweet taste with no calories or harmful effects.
I purchased the miracle fruit in a tablet form off of Amazon. I was reluctant to believe in its sweetening properties; however, after letting the tablet dissolve on my tongue, I was able to eat limes straight without a problem. They even tasted good, and I ate multiple slices, numb to the usual sour effect they have. The berry itself is tasteless, and does indeed provide a miraculous effect that might be a healthy sugar substitute.