In vitro antioxidant and anti-glycation properties of Sargassumhorneri from golden tides on the South Korean coast and the effect on gut microbiota of mice fed a high-sucrose and low-fibre diet

Outbreaks of algal blooms for Sargassumhorneri and Ulva spp., called golden and green tides on the South Korean coast, severely damage the local coastal environment and marine ecological system. However, these edible algae are natural resources of beneficial bioactive components, such as dietary fibres, phenolic compounds, and minerals. In this study, the antioxidant and anti-glycation properties of 2% aqueous extract solution (AES) in vitro from S.horneri (Sh) and Ulvapertusa (Up), and the effects of dried S.horneri and Up on the caecal microbiota of mice fed a high-sucrose and low-fiber diet were investigated. Total phenolic content, antioxidant activity (DPPH radical scavenging and Fe-reducing power), and anti-glycation activity in the BSA-fructose model were higher in Sh-AES than in Up-AES groups. Male Institute of Cancer Research (ICR) mice fed a 5% (w/w) S.horneri diet for 14 days showed a reduced increase in body weight. 16S rDNA (V4) amplicon sequencing results showed that the ratio of Firmicutes/Bacteroidota was reduced after S.horneri and U.pertusa intake. Faecalibaculumrodentium-, Akkermansiamuciniphila-, and Roseburiaintestinalis-like bacteria were enriched in the S.horneri group. Phocaeicolavulgatus-like bacteria were abundant in both the S.horneri and U.pertusa groups. In contrast, the prevalence of Clostridiumdisporicum-like bacteria was low in mice fed the S.horneri diet. Among the bacteria enriched after S.horneri and U.pertusa administration, P.vulgatus was found to be prevalent. From these results, S.horneri from golden tides may be useful as a functional food.