PROBLEM TO BE SOLVED: To provide a composition for improving diabetes symptoms and complications thereof.SOLUTION: The composition is characterized by comprising an effective amount of at least one selected from the group consisting of Lactobacillus reuteri GMNL-89, Lactobacillus gasseri GMNL-205, and Lactobacillus reuteri GMNL-263, and a pharmaceutically acceptable carrier agent. The Lactobacillus gasseri GMNL-205 and the Lactobacillus reuteri GMNL-263 are new isolated lactobacillus strains.