Conclusion
Our data elucidate a novel role for probiotics in glycemic regulation in the host. L. salivarius AP-32 and L. reuteri GL-104 directly reduce monosaccharide transporter expression in gut cells and have potential as therapeutic probiotics for patients with T2DM.
Methods
Sugar consumption by more than 20 strains of Lactobacillus species was first evaluated. The probiotic strains that exhibited high efficiency of sugar consumption were further coincubated with Caco-2 cells to evaluate the regulation of sugar absorption in gut epithelial cells. Finally, potential probiotic strains were selected and introduced into a T2DM animal model to study their therapeutic efficacy.
Results
Among the tested strains, Lactobacillus salivarius AP-32 and L. reuteri GL-104 had higher monosaccharide consumption rates and regulated the expression of monosaccharide transporters. Glucose transporter type-5 and Na+-coupled glucose transporter mRNAs were downregulated in Caco-2 cells after AP-32 and GL-104 treatment, resulting in the modulation of intestinal hexose uptake. Animal studies revealed that diabetic mice treated with AP-32, GL-104, or both showed significantly decreased fasting blood glucose levels, improved glucose tolerance and blood lipid profiles, and attenuated diabetes-mediated liver and kidney injury.