The physiological roles of dietary fibre

The term dietary fibre (indigestible carbohydrates of plant origin) encompasses a range of divergent compounds that differentially affect numerous important gastrointestinal and systemic bodily processes.The main role of the gut is to absorb nutrients following digestion. Complex neurohumoral pathways control gut secretion and motility. Dietary fibres that inhibit intestinal digestive processes result in decreased upper GI transit times, which may affect satiety and satiation.The large intestine houses a varied microflora. Dietary fibre is a major energy source for these bacteria, and therefore markedly affects microfloral diversity/toxicity. Dietary fibres can also affect innate immune responses of the gut mucosa both directly and indirectly.Dietary fibre impacts all processes of the gut, which as a result may impact on cardiovascular/systemic health. As many commonly-used hydrocolloids are viscous, palatable dietary fibres, they have the potential to be used in acceptable foodstuffs that offer a wide range of added health benefits.

Graphical abstractDietary fibre is a term that describes a wide range of non-digestible carbohydrate entities with varying biochemical and biophysical properties. As such, different sources and type of dietary fibre have widely different consequence to human physiology.