Lowering glycemic levels via gastrointestinal tract factors: the roles of dietary fiber, polyphenols, and their combination

Dietary fiber (DF) and polyphenols (DP) are typical blood sugar-lowering components, and both play distinct yet interconnected roles in exerting their blood sugar-lowering effects. We comprehensively summarized the single and combined effects of DF and DP on blood glucose homeostasis through regulating the relevant factors in the upper gastrointestinal tract (UGT) and lower gastrointestinal tract (LGT). In the UGT, DF slowed down glucose metabolism by enhancing digesta viscosity and hindering enzyme-substrate interaction. DP primarily targeted enzymes and substrates. When combined, DP enhanced the adsorption capacity of DF for glucose. DF weakened DP's inhibitory effect on enzymes. Both DF and DP disrupted glucose intestinal uptake via physical or genomic modulation, but the co-consumption of DF and DP demonstrated a lower inhibitory effect on glucose uptake than DP alone. In the LGT, DF and DP showed synergistic or antagonistic effects on gut microbiota. Remarkably, whole foods exhibited potent prebiotic effects due to their compound-rich matrix, potentially enhancing glucose homeostasis and expanding dietary options for glucose regulation research.

Automated summary

Dietary fiber (DF) and polyphenols (DP) have distinct yet interconnected roles in lowering blood sugar levels. DF slows down glucose metabolism by enhancing digesta viscosity and hindering enzyme-substrate interaction in the upper gastrointestinal tract (UGT), while DP primarily targets enzymes and substrates. When combined, DP enhances DF's adsorption capacity for glucose, while weakening DP's inhibitory effect on enzymes. Both DF and DP disrupt glucose intestinal uptake through physical or genomic modulation, but the co-consumption of DF and DP has a lower inhibitory effect on glucose uptake compared to DP alone. In the lower gastrointestinal tract (LGT), DF and DP show synergistic or antagonistic effects on gut microbiota. Remarkably, whole foods have potent prebiotic effects due to their compound-rich matrix, potentially enhancing glucose homeostasis and expanding dietary options for glucose regulation research.