It's not necessary. The roots exude everything the microbes need. Adding sugars to your system just invites the evil microbes you don't want.
I've never tried Mammoth P, but a friend of mine uses it and swears by it. Aother friend uses Tribus and gets good results as well. Both are pricey af. I just run a single strain, bacilus amyloliquefacien, and get healthy roots every time. No sugars.