What is the effect when Mentos and yakult will mixed?

Mixing mentos and yakult can cause a foaming reaction due to the presence of gelatin in Yakult and the rough surface of Mentos mint candy. The gelatin acts as a foaming agent, while the rough surface of the Mentos candy provides nucleation sites for the formation of bubbles. Carbon dioxide gas rapidly escapes from the liquid as a result, resulting in the formation of foam. This reaction is often demonstrated as a fun science experiment due to its dramatic foaming effect.