Lactobacillus rhamnosusReduces Blood Glucose Level through Downregulation of Gluconeogenesis Gene Expression in Streptozotocin-Induced Diabetic Rats

Abstract

Some lactic acid bacteria (LAB) are observed to be potential probiotics with functional properties such as lowering fasting blood glucose (FBG), as a promising hyperglycemia management. This study investigated the ability and mechanism ofLactobacillus rhamnosusBSL andLactobacillus rhamnosusR23 on lowering FBG in diabetic rats induced by streptozotocin (STZ). The rats were orally administered withL. rhamnosusBSL andL. rhamnosusR23 by giving 1 mL cell suspension (109 CFU/mL) daily for 30 days. The body weight (BW) was recorded once in three days, and FBG was recorded once in six days. An oral glucose tolerance test (OGTT) was measured 1 week after injection with STZ and before sacrifice. Fecal samples were collected on days 0, 15, and 30 for LAB population and identification, performed by PCR detecting 16S rRNA. Oral administration ofL. rhamnosusBSL andL. rhamnosusR23 decreased FBG and improved glucose tolerance via downregulation of glucose-6-phosphatase (G6pc) expression by 0.57- and 0.60-fold change, respectively (P<0.05). The lipid profiles, BUN, creatinine, SGOT, and SGPT were significantly (P<0.05) different between normal and diabetic rats, but they were not significantly (P>0.05) different among diabetic rats. Both strains were effective in increasing fecal LAB population. Molecular identification of the isolated LAB from fecal sample indicated that they were able to survive and pass through the digestive tract. These results suggested that both strains have the ability to manage blood glucose level and become a promising agent to manage hyperglycemia and diabetes.