I have read lots of things about Aspartame/Ultra Sweet, however, every single source I find have either been biased or assuming a speculative theory is true, a third kind outright contradict each other. The only facts I could truly conclude when I researched on my own was that it's created from a gene modified coli bacteria, likely the same way insulin is harvested, and that it turns to wood alcohol at body temperature.

Can someone please fill in the blanks?

This is a good article to read:
http://www.madehow.com/Volume-3/Aspartame.html