The analysis of fecal microbiota and insulin production in diabetic rats after oral administration of probiotic Lactobacillus paraplantarum BGCG11

Abstract

Objective Our previous studies with Lactobacillus paraplantarum BGCG11 probiotictreatment of diabetic rats showed decreased hyperglycemia and ameliorating effect on diabetes-associated damage of liver and kidneys. Hence, the aim of this study was to reveal the effects of BGCG11 probiotic on gut microbiota composition and monitoring the insulin production in pancreatic islets in diabetic rats. Methods Experiments were performed on albino Wistar rats divided into four groups: ND – non-diabetic control, D – streptozotocin (STZ) induced diabetes; P/D/P – BGCG11 pretreatment; D/P – BGCG11 treatment. The rats were orally administered with BGCG11, one week before (P/D/P) and after the STZ injection, for four weeks (P/D/P and D/P). Total DNA was isolated from all fecal samples and rDNA amplicons were analyzed by DGGE and 16S rDNA genes sequencing. For immunohistochemical analysis, slides were stained with anti-insulin antibody and secondary antibody coupled with horseradish peroxidase. Results The results revealed the higher diversity of gut microbiota in D/P group comparing to D group, as well as the higher prevalence of Flintibacter butyricus (the major butyric producer), Acetatifactor muris (present in obese mouse) and Eisenbergiella massiliensis (found in obese woman), while the lipolytic bacterium Aestuariispira insulae was more prevalent in diabetic rats. In both, P/D/P and D/P group, increased number of positive immunoreactions of β-cells for anti-insulin antibodies was displayed in compare to D group with islet atrophy. Conclusions The results of this study suggest that the positive effect of BGCG11 on STZ-induced diabetes in rats could be annotated to its protective role on the integrity of fecal microbiota.