Beneficial effects of three brown seaweed polysaccharides on gut microbiota and their structural characteristics: An overview

The gut microbiota appears critical in the metabolic health and anti-disease activity. In this review, we discuss three brown seaweed polysaccharides (alginate, laminarin, fucoidan) for their structural information, the digestive behaviour and the effects on gut microbiota. Bioactivities are associated with various physicochemical properties, like solubility, viscosity, hydration properties, molecular weight, monosaccharide composition, and so on. Brown seaweed polysaccharides can be completely utilised by microbes in the large bowel, and they can regulate the gut microbiota. The ultimate metabolite of these polysaccharides is mainly short-chain fatty acids, which are able to regulate the ecology of the gut microbiota by increasing the growth of beneficial bacteria and inhibiting the growth of some harmful bacteria. In addition, this article also discusses the relationship between the structure and activity of modulating the gut microbiota. Results show that polysaccharides with low molecular weight are more conductive to modulate gut microbiota.