I have no preference either way what people choose - I choose many things at various times including Kim Chi, and even home cultured sourdoughs on occasion - though I tend to limit grains in my diet... people should eat *something* along these lines on a daily basis that is home cultured\fermented.
Even water kefir, kombucha, homemade vinegars, wines and beers - unpasteurized and unfiltered of course... whatever they prefer.
Sourdoughs greatly reduce gluten content... gluten content in grains is increased greatly due to the use of nitrogen fertilizers so there is a hint for you... on what good bacteria can do for you - and how *nitrogen* use in food production has caused disease..
Kim Chi, Sauerkraut, kefir, homemade sourdough breads... taking into account their ancestral origins would likely be a good idea as that food, would likely be their best bet.
Most cultures that did not have much, or any dairy used cabbages of some sort... those that were grain based the sourdoughs... most all of them had beer or wines of some sort... also loaded with beneficial bacteria and nutrients - that is... before bleaching, distillation, filtering, pasteurization, irradiation, etc. took hold in the industries.
>>"Hmm, if you put Kefir into raw milk do you get just Kefir or a combo of Yogurt and Kefir?"<<
You can get a thick yogurt like constancy or soft cheese if you let it go and separate the whey out of it - which you can drink for its benefits too.
NOTE: this homemade stuff is NOT going to be like the junk you buy in the grocery store, with the coloring, gelling and thickener crap they include in the ingredients, so do not expect it to turn out that way.