Renal failure caused by diabetes mellitus , called the diabetic nephropathy (DN), is a serious health problem in the world. Identifying molecular mechanism of the pathogenesis of DN may be helpful in developing new therapeutics. Oxidative stress in mesangial cell caused by hyperglycemia is closely related to the development of DN.BMP-7 helps to maintain renal functions and structural integrity,This molecule, however, disappear early during diabetic nephropathy progression.This study aims to investigate : the effects of lactobacillus reuteri PTCC1655 on serum levels of ?-SMA,PAI-1, Nitric oxide and tissue gene expression levels of TGF-?and BMP-7 as factors involved in renal fibrosis in streptozodotosin-induced diabetic rats.