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