To determine whether the probiotic strain, Bifidobacterium adolescentis Z25 and Lactobacillus reuteri 138-1, isolated from human feces with the function of metabolic syndrome alleviation are edible for subsequent product development, safety of these two strains were assessed. Acute toxicity test, 28-day feeding toxicity test, teratogenicity test and bacterial translocation test were performed. The general appearances, body weight, organ weight, biochemical and hematological indexes of blood, bacterial translocation, histopathological indexes, teratology index of pregnant rats and offsprings were investigated. Except for reduced appetite and body weight gain, no major changes were seen in organ index after probiotics treatment. Except for occasionally non-probiotics-related lung damage, no other tissue lesions and bacterial translocation were detected. No teratogenicity and mutagenicity to the pregnant rat and embryo rat were observed. B. adolescentis Z25 and L. reuteri 138-1 are safe strain without toxicity and side effects.