the idea that certain plants have antifungal properties is not controversial, whatever the precise mechanism. i have little doubt that eating beets or carrots with mushrooms or yeast would help a little; the question isn't whether the information i posted is correct (it is correct) but how useful it is in aiding human digestion of chitin. what i needed to do was find a way to quantify it, and that information doesn't appear to be available via a google search, at least.
search for "carrot" and "chitinase" and you'll see plenty of links - this is a pretty real thing. plants are living creatures, and they have multiple defense systems, including the ability to defend against fungal pathogens. that's basic science, and not up for debate.
so, i'd still suggest that eating beets with yeast, or carrots with mushrooms, is a great idea in principle, and that it will probably help in the way i'm suggesting - but what i'm lacking is a detailed analysis.
so, i'd again call on somebody to do that study and figure it out: how useful is the chitinase in dietary plants (root vegetables, in particular) in breaking down chitin and aiding human digestion of fungi?