Chemical Modification of Cornstarch by Hydroxypropylation Enhances Cecal Fermentation‐Mediated Lipid Metabolism in Rats

Hydroxypropylated (HP)‐cornstarch is fed to rats for 4 weeks and the effects on cecal fermentation and lipid metabolism are evaluated. In the cecum of rats fed either HP‐normal cornstarch (NCS) or HP‐waxy cornstarch (WCS), microbial composition is altered and the relative abundances of the Firmicutes and Bacteroidetes are decreased and increased, respectively, compared to high amylose cornstarch (HACS), NCS, and WCS groups. Cecal total‐short‐chain fatty acid (SCFA) content in the rats fed HP‐NCS and HP‐WCS is higher than the rats fed NCS and WCS. In HP‐NCS and HP‐WCS groups, cecal pH and mesenteric adipocyte area are decreased, and the plasma glucagon‐like peptide‐1 (GLP‐1) level and cecal mucin content are increased compared to HACS, NCS, and WCS groups. Plasma GLP‐1 level correlates positively with the cecal SCFA content and the serum insulin level, and negatively with the feed intake, while the adipocyte area positively correlates with the serum triglyceride level. Therefore, HP‐cornstarch may have possessed beneficial traits that enhance cecal fermentation and thereby influenced lipid metabolism, equally or greater than that of HACS. Hydroxypropylation of cornstarch increases the resistance to digestive enzymes. In this study, hydroxypropylated‐cornstarch fed rats exhibited altered cecal microbial composition, increased cecal short‐chain fatty acid (SCFA) content and reduced mesenteric adipocyte size.