In vitro antioxidant and antiglycation properties of Eisenia bicyclis stems and their effects on the gut microbiota of mice fed a high-sucrose and low-fibre diet.

The fronds of the brown alga Eisenia bicyclis are regarded as healthy foods and are used as skin care agents because they are rich in dietary fibres, minerals, and antioxidant compounds. However, E. bicyclis stems have been overlooked thus far. In this study, we determined the in vitro antioxidant and antiglycation properties of E. bicyclis stems and their dietary effects on mice fed a high-sucrose and low-fibre diet. The total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, ferric-reducing power, and antiglycation activity of the E. bicyclis stem-aqueous extract solution were higher than those of the fronds. The diet containing 5% (w/w) dried E. bicyclis stems increased excretion frequency and faecal and caecal weight and decreased plasma cholesterol levels. The abundance of Bacteroidaceae family and Akkermancsia muciniphila-, Bacteroides acidifaciens-, Phocaeicola vulgatus-, and Parabacteroides goldsteinii-like bacteria increased in E. bicyclis stem-fed mice. These results suggested that E. bicyclis stems could be a source of functional foods and cosmetic products. [ABSTRACT FROM AUTHOR]