Possible actions of inulin as prebiotic polysaccharide: A review

Abstract

This review summarizes the nature, types, and properties of inulin polysaccharides and their applications as prebiotic dietary fibers. Natural food and commercial plant sources of inulin and extraction methods are presented. The physicochemical and functional properties of inulin are summarized. The prebiotic roles of inulin and their mechanisms of action are detailed. Inulin acts as prebiotic dietary fiber with multiple putative health benefits. It reduces caloric intake and contributes to reduced blood glucose and plasma lipid/cholesterol levels when used as sugar and fat replacers. It also stimulates immune systems and protects the colon mucosa against carcinogenesis and inflammation. Inulin also alters the composition and population of the gut microbiota. It stimulates the growth and activities of health beneficial microorganisms while inhibiting enteropathogenic bacteria. The beneficial microorganisms ferment inulin and produces acids including short-chain fatty acids that lower the pH in the colon and inhibit pathogens. The health beneficial bacteria also produce other metabolites that positively influence human health. The consumption of inulin is however, associated to symptoms of gastrointestinal discomfort, when consumed at higher levels to meet the daily recommendation of dietary fiber. Potential solutions to the limitations are forwarded as future research ideas and policy inputs.