two good books regarding kefir and the health benefits of same, and how to
make kefir easily with many substances other than dairy:
wild fermentation - by sandor ellix katz
the body ecology diet - by donna gates
these books do not promote neanderthin / paleo styles and beliefs, but you
will find some nice recipes and lots of thought-provoking info and
techniques that often compliment paleo-eating standards.
---BONNY in Kentucky (lurker here for many years, not paleo yet tho!)