Isomaltodextrin, a highly branched α-glucan, increases rat colonic H2 production as well as indigestible dextrin

Colonic hydrogen (H 2 ) protects against inflammation-induced oxidative stress. We examined the effect of a new highly branched α-glucan, isomaltodextrin (IMD), on colonic H 2 production in rats. Rats were fed a 16.7% IMD, 8.8% indigestible dextrin (ID), or 10.4% high amylose cornstarch diet (Expt. 1), were fed diets containing 3.3-16.7% IMD (Expt. 2), or were fed diets containing 16.7% IMD or 5.2% fructooligosaccharide (FOS) (Expt. 3), for 14 days. Compared with the control group, feeding IMD or other α-glucans dose dependently and significantly increased H 2 excretion and portal H 2 concentration. The ability of IMD to increase H 2 production was not inferior to that of FOS. The cecal Firmicutes/Bacteroidetes ratio in the IMD group was 5-14% of that in the control group. The cecal abundance of bifidobacteria was significantly greater in the IMD group than in the control group. Taken together, IMD, as well as other α-glucans, significantly increased colonic H 2 production in a dose-dependent manner. Isomaltodextrin(IMD), a highly branched α-glucan, dose dependently increases colonic H 2 generation and decrease cecal Firmicutes(F)/Bacteroidetes(B) ratio.