The invention relates to a composition for improving the syndrome of diabetes and complication thereof. The composition comprises an effective amount of Lactobacillus strain which is at least one selected from the group consisting of: Lactobacillus reuteri GMNL-89 strain, Lactobacillus gasseri GMNL-205 strain, Lactobacillus reuteri GMNL-263 strain and a pharmaceutical acceptable vehicle. The Lactobacillus gasseri GMNL-205 strain and Lactobacillus reuteri GMNL-263 strain are novel isolated Lactobacillus strains. In addition, the invention also relates to a novel use of the compositon or the Lactobacillus strains for improving the syndrome of diabetes and complication thereof.