(P20-042-23) Combined Resistant-Dextrin and Low-Dose Magnesium Oxide Administration Increases Short-Chain Fatty Acid and Lactic Acid Production by Gut Microbiota

Objectives: Consumption of nondigestible nutrients, including resistant dextrin, improves constipation. In addition, fermentation and degradation of resistant dextrin by the intestinal microbiota produces short-chain fatty acids (SCFA) and lactic acid, which have beneficial effects on host metabolism and immunity. Magnesium oxide (MgO), an important mineral, is used as treatment for constipation. Therefore, resistant dextrin and MgO are often administered together to improve constipation; however, limited information is available regarding the effect of this combination on SCFA and lactic acid production.

Methods: Crl:CD1(ICR) mice were fed a magnesium-free diet with 5% resistant dextrin followed by oral MgO administration. We collected the cecum contents and measured SCFA and lactic acid. Additionally, human subjects also received additional resistant dextrin and magnesium supplements as part of their habitual diet.

Results: Results from this study demonstrated that intestinal microbiota cannot promote SCFA and lactic acid production in the absence of magnesium. In the mouse model, low doses of MgO promoted the production of SCFA and lactic acid, whereas high doses decrease this production. In humans, the combined consumption of resistant dextrin and magnesium supplements increased the production of SCFA and lactic acid.

Conclusions: In conclusion, the production of SCFA and lactic acid from dietary fiber, might be augmented by the presence of MgO.

Funding Sources: This work was partially supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (Houga) [Shibata. S], and JST-Mirai Program Grant Number JMPJM120D5 (Japan; S. Shibata).