Infection by Klebsiella pneumonia producing class A carbapenemases is a major clinical and public health problem in Israel and worldwide. The aim of this study is to determine the safety and efficacy of alteration of the gut microflora by probiotics, alone or in combination with mechanical bowel cleansing, as a strategy to eradicate colonization of the gastrointestinal tract by CRKP. We hypothesize that administration of probiotics will decrease the rate of GI colonization by CRKP.