Polydextrose, as a typical representative of soluble dietary fiber, has attracted academic attention in recent years due to its unique regulatory function of sugar metabolism. This article will systematically analyze the principle of its effect in reducing sugar absorption from three dimensions: molecular mechanism, clinical research, and application scenarios, and explore its potential value in the prevention and control of chronic diseases.

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I. Physicochemical Properties and Metabolic Characteristics of Polydextrose
Structural particularity
A branched polymer formed by high-temperature polymerization of glucose, sorbitol and citric acid, with a molecular weight range of 1000-12000 Da, and an anti-digestion structure mainly composed of β-1,6 glycosidic bonds.
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Physiological behavioral differences
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Intestinal hydrolysis rate < 10% (vs starch > 90%)
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The calorie content is only 1kcal/g (4kcal/g for regular sugar).
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Viscosity: 50-200 mPa·s (10% solution at 25℃)
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Ii. Four Major Mechanisms of Reducing Sugar Absorption
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(1) Physical barrier effect
By forming a high-viscosity colloid to delay gastric emptying (delayed by approximately 40 minutes), the contact efficiency between chyme and small intestinal villi is reduced. Animal experiments showed that it could reduce the peak concentration of glucose by 28% (p<0.05).

(2) Competitive inhibition
The binding capacity with the SGLT1 transporter reaches 63% of maltose, reducing the active transport of monosaccharides. The in vitro Caco-2 cell model confirmed that its efficiency in inhibiting glucose transport reached 35±7%.

(3) Microbial fermentation regulation
Colonic fermentation produces short-chain fatty acids (SCFAs), stimulating the secretion of GLP-1 (increasing by 2.1 times) and enhancing the function of pancreatic islet β cells. Metagenomic analysis revealed that it could increase the abundance of Bifidobacteria by 8.3 times.

(4) Enzyme activity interference
The activity of α -amylase was inhibited by steric hindrance (IC50=3.2mg/mL). In vitro experiments showed that the starch hydrolysis rate decreased by 42%.

Iii. Systematic Analysis of Clinical Evidence

Study type Sample size Intervention plan Changes in glucose absorption Literature source: RCT45 cases T2DM15g/d×8 weeks HbA1c↓0.9%Nutr J 2023 Crossover design 24 Healthy individuals 10g single dose GI value reduction 22Br J Nutr The 2024 cohort study included 1,560 individuals with a long-term intake of Diabetes risk ↓34%Diabetes Care 2022

Iv. Key Technologies for Industrial Application
Innovation in Food Engineering
Replacing 30% sucrose in baked goods does not affect the taste
When compounded with erythritol, it can mask the aftertaste
Microencapsulation technology enhances thermal stability (resistant to 180℃)
Precise dose recommendation
Daily maintenance: 8-12g/ day
Abnormal glucose tolerance: 15-20g per day
Maximum tolerated dose: 50g/ day (Excessive intake may cause osmotic diarrhea)
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V. Application Guidelines for Special Groups
Gestational diabetes: It is recommended to take it in divided doses (3×5g per day)
Elderly people: Take calcium supplements in combination to prevent interference in mineral absorption
Athlete: Avoid using it within 2 hours after training to prevent insufficient energy supply
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Outlook
With the development of gene sequencing technology, personalized fiber supplementation plans based on the characteristics of the intestinal flora may be realized in the future. The current technical bottlenecks that need to be broken through include:
① Establish a more accurate dose-effect relationship model
② Develop delivery systems targeting colonic release
③ Clarify the synergistic mechanism with other nutrients