Background
Excessive intake of saccharides leads to an increase in body weight and contributes to the development of type 2 diabetes. Specific polyphenols have been shown to directly inhibit or, conversely, promote saccharide absorption although data are scarce and not in agreement. The effects of polyphenols on the modulation of gene expression of these transporters are currently unknown.

Objectives
The primary objective of the study was to investigate the effects of different polyphenols belonging to class A or B, on the expression of monosaccharide transporters SGLT1, GLUT2, and GLUT5. The secondary objective was to determine the role of AMPK activation in the cellular pathway through which polyphenols potentially modulate the expression of monosaccharide transporters.

Study design
Differentiated caco-2 cells were pre-incubated with different concentrations of the polyphenols for 4 hours. After incubation, glucose and NBD-fructose were added and it’s absorption across the epithelium was measured. The glucose concentrations was determined with the Amplex red assay and fluorescent signal of the NBD-fructose was measured.

Results
The polyphenols belonging to class A increased the absorption of glucose (+19%, p<0,01)  across the intestinal barrier, while class B polyphenols caused a reduction in glucose uptake (-21.3, p<0,0001) as well as in fructose uptake (-73.1%, p<0,01). Preliminary results indicate that the class B polyphenols reduced the gene expression of SLGT1 in differentiated caco-2 cells (fold change 0.8).

Conclusion
This study showed that specific polyphenols can inhibit intestinal saccharide absorption, thus revealing the potential of the polyphenols for use as a therapeutic compound in preventing diabetes. However, choosing the correct class of polyphenol to reduce saccharide absorption is critical.  The next step in this study is to investigate the role of AMPK activation in reducing saccharide transporter expression.