Influence of Lactobacillus brevis 15 and Lactobacillus plantarum 13 on blood glucose and body weight in rats after high-fructose diet

In recent years, many authors have investigated the possible antidiabetic effect of lactic acid bacteria. Lactobacillus species constitute a major part of the lactic acid bacteria group and have been found to exhibit beneficial effects on the development of diabetes and its complications. In the current study, we investigated the effects of newly characterised Bulgarian Lactobacillus strains, Lactobacillus brevis 15 and Lactobacillus plantarum 13, on blood glucose levels and body weight of rats fed a fructose-enriched diet. An experiment was conducted over a period of 8 weeks with 24 2-month-old Wistar rats randomly assigned to receive a standard diet (Con, control group), fructoseenriched diet (Fr group), standard diet with probiotics given twice a week (Pro group), and fructose-enriched diet with probiotics given twice a week (Pro+Fr group). At the end of the experimental period, a statistically significant increase in body weight was observed in all experimental groups (P<0.0001). The highest rise was seen in the fructose group (Fr, 169 +/- 19 g), followed by the Pro+Fr group (153 +/- 15 g), Pro group (149 +/- 13 g), and Con group (141 +/- 5 g). Moreover, the final blood glucose levels had risen significantly in the groups receiving fructose either without (Fr; P<0.0001) or with lactobacilli (Pro+Fr; P=0.002), while the rise was insignificant in the group of rats given probiotic supplementation only (Pro, P=0.071) and inexistent in the Con group (P=0.999). The highest elevation of blood glucose levels was observed in the Fr group (3.18 mmol/l), followed by the Pro+Fr group (2.00 mmol/l) whereas the Pro group showed the lowest levels (0.60 mmol/l). The results of our study suggest that the newly characterised Bulgarian Lactobacillus strains, L. brevis 15 and L. plantarum 13, could be considered as possible probiotics and might be able to prevent some metabolic disturbances.