Current trends in marine algae polysaccharides: The digestive tract, microbial catabolism, and prebiotic potential

Marine algae contain unique polysaccharides which differ from terrestrial plant polysaccharides, having a different composition, substitution, and linkage types. These are non-digestible by digestive enzymes in humans. Remarkably, marine algae polysaccharides (MAPs) may selectively enhance the activities of some populations of beneficial bacteria and stimulate the production of functional metabolites by gut microbiota. The MAPs also stimulate a range of biological activities, such as anti-cancer, anti-oxidant, immune-modulatory, and anti-diabetic. There is great potential to explore prebiotic MAP compounds. However, the exact digestion and fermentation behaviors in the human gastrointestinal tract, as well as their beneficial physiological effects, are to a large extent unexplored. An in-depth investigation of MAPs will provide us novel insights into the specific fermentation behavior for the observed human gut benefits. This paper is envisioned to offer a new perspective on the sustainability-promoting applications of MAPs as prebiotics in the functional food and pharmaceutical industries.