Abstract: Objective We aimed to obtain a strain of probiotics from lactobacillus bulgaricus capable to decompose uremic toxins, to provide a new strain of intestinal bacterium for the treatment of chronic renal failure. Method The original lactobacillus bulgaricus was induced by incubation in uremic patients’sera, and then repeatedly induced by physical (ultraviolet radiation) and chemical (diethyl sulfate) methods. We used the decomposition ability to creatinine as the index, to select the strains capable to efficiently decompose creatinine, and then to test their genetic stability and their decomposition abilities to urea, uric acid, serum phosphate, parathyroid hormone, and homocysteine. Result After the inductive and mutagenic treatments, we obtained a strain of DUC3-17. The decomposition rates of this strain for creatinine, urea nitrogen, uric acid, phosphorus, parathyroid hormone and homocysteine were 17.23%, 36.02%, 9.84%, 15.73%, 78.26%, and 12.69%, respectively. These abilities were stable after 5 passages. The original lactobacillus bulgaricus did not have these abilities. Conclusion We used directed induction and physical and chemical methods to lactobacillus bulgaricus, and obtained a mutant strain that has greater abilities to decompose uremic toxins and was genetically stable.

Key words: Lactobacillus bulgaricus, Creatinine, Chronic renal failure, Uremic toxins