Measuring the effect of Mankai® (Wolffia globosa) on the gut microbiota and its metabolic output using an in vitro colon model

Abstract

• Wolffia globosa an emerging functional food, targets obesity and metabolic disease. • Wolffia globosa rich in fiber and polyphenols modulates the gut microbiome. • Wolffia globosa increases microbiota phenolic acid and SCFA production in vitro. • Microbiome modulation may underpin certain health effects of Wolffia globosa ingestion. Mankai® is a cultivated strain of Wolffia globosa an aquatic plant of the family Lemnaceae commonly known as Duckweeds. Recent studies suggest that consumption of a Mankai® enriched diet may provide positive health effects by decreasing body weight and improving glucose homeostasis and plasma lipid profiles. However, the effects of Mankai® alone on the composition and metabolic output of the human gut microbiota has not been fully investigated. Here, Mankai® was digested and fermented in vitro using a batch culture model of the proximal colon. Inulin and cellulose were used as readily and poorly fermentable control fibers respectively. Mankai® significantly stimulated the production of phenolic metabolites and short chain fatty acids by the gut microbiota (p<0.05). Three major microbial metabolites, 3-4-hydroxyphenyl propionic acid, 3-3-hydroxyphenyl propanoic acid and protocatechuic acid were significantly increased after 24 h fermentation. Moreover, Mankai® treatment lowered the overall microbial diversity (p<0.05), in line with a selective microbiome modulation.