I think genetic is part of it, education (eating habits) too, as well as the presences of specific bacteria. Not much is known about candida or about chronic diseases in general. We merely begin to understand the influence of intestinal flora over the whole body (and they now call it the 2nd brain to give it back the importance it deserves).
:Like the brain your flora can influence on your desire to eat sugar, your choices and EVEN have some preferential genetic info being expressed as opposed to others. I now see it as a blessing that i could find out early about candida and change my eating habits to eat what is best for me.