Howdy, Cyndy. Heather has some good information about prebiotics on the site. If you do a google search for "inulin" there should be a link to info on nutrition.org and from there you can read about it and link to other studies. But I think badlydrawnboy answered your first question, so I'll answer the one regarding my diet.
I don't take a probiotic supplement. Right now I'm just getting the inulin from Luna Bars and Teeccino (inulin usually comes from chicory), probiotics from soy yogurt (I was eating sauerkraut for a while per dr's recommendation but it made me too gassy--this was before learning about Heather's diet, so I may add it back in, with a good SF base. Maybe!), and I use Benefiber (guar gum--although I haven't been taking it as regularly). Other than cultured dairy/soy-alternative products, I don't know what other fermented foods are available. Oh, I think tempeh is another good source.