I looked at the documents of the above article and I did not find that it says "excrement" is used. What I did find is it is a very involved process and it does use one of the E. coli bacteria of which there seems to be many variants. I'm not saying that aspartame is good for a person, I think it is not, but I find that Natural News embellishes things a tab bit for the fear-factor. I am beginning to think that Natural News is on the same level as The People's Voice and Slay News. But that's just my opinion.
