earticle

영어

Functional roles of starch besides a carbohydrate energy source have been recently focused on the regulation of gut microbiota which can derive to various prebiotic benefits such as anti-obesity and hypoglycemic effects as a diabetes-preventive strategy. Our attempts were to identify prebiotic starch sources and investigate the prebiotic functions. Firstly, the effects of various starches on the gut microbiota were investigated using normal chow diets formulated based on AIN93G but replaced corn starch to potato, rice, and wheat starch. Potato starch-based diet prevented the development of obesity and insulin resistance through the slowest digestion property of potato starch by mammalian mucosal α-glucosidase and also it caused obviously changed microbial community. For instance, the ratio of Bacteroidetes to Firmicutes was significantly increased by potato starch-based diet compared to diets based on other starches and predictably an increase in the abundance of Akkermansia which has known to be beneficial for diabetes treatment was found. These indicate that digestion property of starches may be a key to regulate the gut microbial community. Secondly, we investigated the prebiotic effects of resistant starch whose proportion was increased by structural modification of chestnut starch by amylosucrase from Deinococcus geothermalis (DGAS) in diet-induced obesity animal model. Chest starch modified by DGAS (DMCS) showed significant anti-obesity effects related with short chain fatty acids (SCFA) receptor GPR43-mediated suppression of insulin signaling pathway in white adipose tissue. Concurrently, the mechanisms of energy expenditure were activated by DMCS, mediated by the significant changes in microbial community such as Ruminococcus, Ruminococcaceae, Prevotella etc and the metabolites such as SCFA particularly acetic acid which were significantly correlated with the expression of genes involved in GPCR signaling, fatty acid oxidation, and the ATP-formation pathway.