Simulated digestion, dynamic changes during fecal fermentation and effects on gut microbiota of Avicennia marina (Forssk.) Vierh. fruit non-starch polysaccharides.

Grey mangrove (Avicennia marina (Forssk.) Vierh.) fruit is a traditional folk medicine and health food consumed in many countries. In this study, its polysaccharides (AMFPs) were obtained and analyzed by chemical and instrumental methods, with the results indicating that AMFPs consisted of galactose, galacturonic acid, arabinose, and rhamnose in a molar ratio of 4.99:3.15:5.38:1.15. The dynamic changes in AMFPs during the digestion and fecal fermentation processes were then investigated. The results confirmed that AMFPs were not depolymerized by gastric acid and various digestive enzymes. During fermentation, 56.05 % of the AMFPs were utilized by gut microbiota. Galacturonic acid, galactose, and arabinose from AMFPs, were mostly consumed by gut microbiota. AMFPs obviously decreased harmful bacteria and increased some beneficial microbiota, including Megasphaera, Mistuokella, Prevotella, and Megamonas. Furthermore, AMFPs obviously increased the levels of various short-chain fatty acids. These findings suggest that AMFPs have potential prebiotic applications for improving gut health.

Isolation, structures and biological activities of polysaccharides from Chlorella: A review.

Chlorella, a green microalga, has been used as an important ingredient in food and medicine because of its excellent nutritive and functional properties. Polysaccharides, as major active ingredients of Chlorella, have attracted increasing attention due to their various health promotion activities, such as those associated with immunomodulation, antioxidation, anti-hyperlipidemia, antitumor, neuroprotection, and anti-asthmatic effect. The significance of polysaccharides from various species of the Chlorella genus has been extensively reported by the scientific community from the perspectives of extraction, structural features, biological activities, and potential uses, which need to be reviewed to improve the understanding, development and utilization of these species. Therefore, this review aims to comprehensively summarize previous and current references regarding the extraction, purification, structural characterization and biological activities of polysaccharides from Chlorella. Moreover, this review also highlights the challenges of investigation and future considerations for holistic utilization in food and medicine.