Hi Jeana,
I don't have a problem with yeast anymore since my doctor prescribed a 12 strain, 25 Billion plus probiotic. There are several brands -- they are found in the refrigerated section of your health food store. The Vitamin Shoppe carries it discounted. I just take one a day -- and if I were to have a problem two a day temporarily (can cause diarrea with two). The cost is about $45 for a two month supply.
I haven't had to take Diflucan since taking these probiotics.
Probiotics also help with the immune system in other ways. Recent studies show that they have their own pathways in the digestive system and I cannot remember exactly but stimulate a certain kind of T cell (T1 or T2 --sorry I can't recall) which are fighter cells. So there are many other benefits other than reducing yeast.