RJK
Yeah, it is one of those things people argue about. Fermented foods or not. Yeasty foods or not. Lentils or not.
If you have a digestion problem, then cabbage (fermented or not) can sometimes be rough on it - due to the fiber. This may be more an issue for the IBD crowd though.
The fermented juice can be taken without issues for most people with IBD/IBS, but not completely sure about the candida subgroup.
Similarly, some people have trouble consuming yogurt (24 hour fermentation, minimal lactose), but for people like me it has been a godsend and a way to regain weight.
Further, some claim that yeasty foods such as nutritional yeast to be bad for people with candida - but likewise, some clinicians use it with success in people with chronic fatigue, etc.
So all you can do is judge the effect for yourself.
The best way to do this, would be to introduce it once you have some of your symptoms under control - that way you can see the effect it has. Remember to wait up to a week for any problems to show, and also be mindful that some symptoms can be "die off" (i.e. the flu-like symptoms you get from endotoxin release of dead micro-organisms).
So do whatever diet you feel like, wait until you feel somewhat stable, then try some fermented cabbage juice and see how you go.
And tell us.
good luck.
RJK.