Okey dokey!
There is recent research supporting the use of probiotics in CRF kitties to help bring down BUN/Creatinine. It worked well in most cats, and even the few that didn't have changes in the bloodwork clearly felt better. The product used was Azodyl (
http://www.kibowbiotech.com/our_productsvet.php), but I don't see why any good (human) probiotic wouldn't help as well. I say human, because tests on both human and veterinary probiotic products have found that the vet products have no live organisms, whereas the human products at least had some (though rarely what was claimed on the label).
I think it was Purina that published studies last year "proving" that their renal veterinary diet increases lifespan in both cats and dogs. That had never been documented in cats before. However, since Purina did the study on their own product, I'd be taking those results with a barrel of salt!
In my experience, there are some cats who will do better on a renal diet to manage symptoms, but it's problematic at best for most cats because they won't eat it! My personal philosophy is this: if someone told me I could live an extra ten years by giving up Ben & Jerry's, I'd take the ice cream!

I'm not about to take away the foods my cats love so much and force them to eat something that's "good for them"--where's the joy in that? But everyone has to make that decision based on their own ideas and circumstances.
Just FYI, here's my general article on kidney disease:
http://www.littlebigcat.com/index.ph...=show&item=003