Much like yogurt, it's made by fermentation. Much like table salt, it was discovered to be delicious by people putting just about everything in their mouths back in the day. It can be said that MSG was in the process of being well-studied early on when the sensationalized news fouled up the whole process and made people unnecessarily afraid of something no more harmful than table salt.
Decades and tens to hundreds of papers later, the sensationalized story is still winning in the minds of people who don't understand how science works and don't know where most of the stuff around them comes from. This is the problem with overreacting to a headline. You might be doing yourself a favor health wise, possibly, but you might also be demanding millions of restaurants redesign their menus to feed you less healthy, less delicious food, for no good reason.
The problem is, you don't know. That's why it's okay to take a single paper with a grain of salt.