Specific Lactobacillus probiotic strains may support glucose homeostasis, addressing physiological parameters of insulin resistance and glucose intolerance, according to a recent in vitro study published in the Nutrition Research Journal (DOI: https://doi.org/10.1016/j.nutres.2020.11.008).
Researchers from the University of Maribor used probiotic bacterial strains Lactobacillus plantarum PCS20 (PCS20), Lactobacil plantarum PCS26 (PCS26), Lactobacillus rhamnosus GG (LGG) and Lactobacillus acidophilus, examining their effects on SGLT1, GLUT2— glucose transporters, gene transcription and expression, and transepithelial glucose transport in human epithelial colorectal adenocarcinoma cells (Caco-2).
Glucose absorption and transport in the gut impact blood levels following food consumption. As noted in the paper, sodium-dependent glucose cotransporter SGLT1 is “responsible for glucose uptake from the intestinal lumen … and … GLUT2, responsible for the transepithelial glucose transport from the cell into the systemic circulation.” In other words, SGLT1 absorbs the glucose present in the intestine, and GLUT2 allows for that absorbed glucose to reach the blood and be transported around the body.
Results revealed all Lactobacillus probiotic strains upregulated SGLT1 gene expression and downregulated GLUT2 gene expression. The L. acidophilus strain increased GLUT2 downregulation by a statistically significant 1.42-fold. Furthermore, “a reduction in protein levels has been observed for all strains, which is consistent with the downregulation tendency of GLUT2 gene transcription in all samples. Moreover, L. acidophilus seemed to have the most potent effect on GLUT2 protein production by reducing the level to 67% ... most likely via downregulation of GLUT2 gene transcription … followed by PCS20 (80%), PCS26 (88%) and LGG (91%).” Lactobacillus probiotic strains were found to decrease blood glucose levels.
Based on results, researchers concluded that “specific strains belonging to the genus Lactobacillus can effectively change transepithelial intestinal glucose transport in vitro.”; thus, opening a promising opportunity for the probiotic industry to develop probiotic supplements to support healthy blood glucose and insulin levels.