Table 1 Dietary fibre- physico-chemical characteristics and relationships to gut effects (modified from [9])
| DF characteristic | GIT effect | Systemic effect | References |
|---|---|---|---|
| Water-holding capacity & viscosity |
Slows gastric emptying; Changes digesta mixing; Alteration of digestive enzyme activity; Stimulates passage rate; |
Slows digestion, especially of protein and lipids; Associated with reduced plasma cholesterol; Blunting of glycaemic response | [11,12,13] |
| Bulking |
Gastric distension; Changes in mixing & diffusion; | Decrease food intake; | [14, 15] |
| Adsorption of compounds (e.g. bile salts, polyphenols & minerals) |
Increases bile acid excretion & other compounds; Retention of polyphenols until large intestine; | Blood cholesterol; fermentation of polyphenols; | [16, 17] |
| Encapsulation | Plant cell walls encapsulate e.g. starch granules; | Transport of starch (resistant) to LI for fermentation; | [18,19,20,21] |
| Fermentability |
Increases microbial biomass & fermentation end-products (e.g. SCFA); Induces selection of specific microbes; | Energy for colonocytes; influences satiety; faecal bulking; “colonization resistance” to pathogens; | [22, 23] |