The problem with Kefir is the yeast present in it. Most candida sufferers react to yeast in a way or other.
Isn’t this because the probiotic yeasts compete with candida, producing die-off? It makes a case for starting slow, but probably not for complete evasion. You could make a similar point about s. boulardii.
I know people who have reported they can not tolerate S. Boulardii.
No my case, thanks god.