Potential use of seaweed polysaccharides as prebiotics for management of metabolic syndrome: a review

Seaweed polysaccharides (SPs) obtained from seaweeds are a class of functional prebiotics. SPs can regulate glucose and lipid anomalies, affect appetite, reduce inflammation and oxidative stress, and therefore have great potential for managing metabolic syndrome (MetS). SPs are poorly digested by the human gastrointestinal tract but are available to the gut microbiota to produce metabolites and exert a series of positive effects, which may be the mechanism by which SPs render their anti-MetS effects. This article reviews the potential of SPs as prebiotics in the management of MetS-related metabolic disturbances. The structure of SPs and studies related to the process of their degradation by gut bacteria and their therapeutic effects on MetS are highlighted. In summary, this review provides new perspectives on SPs as prebiotics to prevent and treat MetS.

Galactans of Gracilaria pudumadamensis (Gracilariales, Rhodophyta) of Indian Waters

Galactans from the Indian agarophyte Gracilaria pudumadamensis were extracted and characterized. The isolated native (GPNative) and alkali treated (GPAlkali) galactans were characterized by IR, 13C NMR, GC-MS and GPC. It was found that GPNative and GPAlkali were composed mainly of 3,6-anhydro L-galactose, 6- O-methylated D-galactose and galactose in various mole proportions (15.6:69.9:17.5 mole% for GPNative and 20.2:69.8:10.0 mole% for GPAlkali). The GPNative and GPAlkali exhibited low gel strengths (<100 g/cm2) and high melting points (~76 °C), which may be due to the presence of high 6- O-Me-galactose contents. The latter, having low sulfate (2.1%), was by far the greatest 6- O-Me-galactose containing polysaccharide in a Gracilaria spp. reported in the literature. This methylated agar contained very low heavy metal ions estimated by inductively coupled plasma spectrophotometry (ICP). The results of this investigation would be useful in bioprospecting of agarophytes, especially those occurring in Indian waters and would be potentially useful in food, personal care and related domains.