The study is design to be double blind placebo control, in the first 3 month patients will be with no therapy and will be required to record all there FMF episodes and their GIT adverse effect, in the second period the patients will be randomly divided into two groups 1.patients that will received placebo (group 1) and the 2. Probiotics group - patients will received probiotics (Bio -25 including 11 types of bacteria L.acidophilus, B.bifidum , L.rhamnosus, L.lactis, L.casei, B.breve, B.thermophilus, B.longum, L.paracseis, L.plantarum, B.infantis), both for three month, during this period patient will be required to record their gastrointestinal symptoms and other symptoms that may be related to FMF.