I recently did a food intolerance test and my immune system reacts to all the products made out of cow... Kefir included. 

So would test that out. 

Really, there's no solution that suits everybody. Need to do your own research. 

Btw, was eating carnivore for a bit of time & fucked up my digestive system & liver too... Just couldn't handle as much protein & now have to eat lots of veggies (and beef too 2x per week) to fix it up. 

In other words - do your own research.