Biological activities of water‐soluble polysaccharides from Opuntia humifusa stem in high‐fat‐diet‐fed mice

Water‐soluble polysaccharide (WSP) of Opuntia humifusa stems was extracted and its biological activities in mice fed with a high‐fat diet (HFD) were investigated. The mice were treated with oral doses of WSP for 4 weeks. Body weight, fat mass, serum lipid, and hormone profiles, gastrointestinal tract changes were evaluated. WSP treatment resulted in a decrease in fat mass and improvement of lipid and hormone profiles associated with HFD consumption. In addition, WSP improved the gastrointestinal health of the mice by increasing ghrelin‐releasing cells and serotonin‐positive cells and boosted immune functions by increasing the expression of CD4+ cells and nitric oxide synthase. Also, WSP treatment reduced gastrointestinal transit time and increased fecal moisture content. These findings suggest that a sufficient intake of WSP from O. humifusa can be beneficial in preventing disorders that are associated with the consumption of HFD including the preservation of gastrointestinal health. Practical applications Opuntia humifusa is a traditional edible plant widely eaten in Asia for its high concentrations of vitamin C, polyphenols, and flavonoids. The research investigated the biological activity of WSP extracted from O. humifusa stems. The data obtained from this study sheds light on the use of plant‐based polysaccharides in nutraceutical industries as potential functional food materials for the prevention of HFD‐related disorders and improvement of gastrointestinal health. The results of this research could serve as a base for further research on this polysaccharide as a source of functional polysaccharides and promotes its usage on a large scale in functional food materials.