Indigestible Dextrin Alleviates the Intestinal Absorption of Alpha-linolenic Acid More Markedly Than That of Linoleic Acid in Obese Mice

Abstract Linoleic acid (LA) and alpha-linolenic acid (ALA) constitute the main dietary polyunsaturated fatty acids. Indigestible dextrin (DEX) is a dietary fiber that causes a beneficial decrease in lifestyle-related disease risk factors. We investigated the effects of DEX on intestinal absorption of LA and ALA in obese mice. KK-Ay/TaJcl obese mice were fed an ALA- or LA-abundant diet and provided with water in the absence and presence of 0.06 w/v% DEX for 4 weeks. The levels of lipids in serum samples and the lipase activity in serum and liver were analyzed. The effects of DEX on the intestinal absorption of LA and ALA were investigated using an in vitro model of the intestinal absorption process in the fed-state simulated intestinal fluid (FeSSIF) solution. ALA resulted in an increase in the serum triglyceride (TG) levels than those observed upon feeding an LA-abundant diet. DEX suppressed significantly the ALA-dependent increase in serum TG levels. Neither LA nor ALA affected the serum levels of total cholesterol and high-density lipoprotein cholesterol, as well as the serum and hepatic lipase activities. Moreover, ALA showed better solubility than LA in FeSSIF solution. The solubility of ALA in FeSSIF solution was significantly suppressed by DEX, whereas that of LA was not affected by DEX. ALA can be absorbed more easily than LA during the intestinal absorption process, probably leading to an increase in the serum TG levels and then DEX more selectively inhibits the intestinal absorption of ALA compared to that of LA. GRAPHICAL ABSTRACT