Effects of Waxy Maize Starch and Malate-Debranched Waxy Maize Starch on Gut Microbiota of Humans In Vitro and Mice In Vivo

The gut microbiota plays a pivotal role in host health. Dietary components such as waxy maize starch (WMS) and malate-debranched WMS (MADBS) may serve as modulators of microbial composition and function. In this study, the effects of WMS and MADBS on murine gut microbiota in vivo and human fecal in vitro fermentation were investigated. The results of gut microbiota in mice revealed that WMS increased the abundance of Muribaculaceae and Bifidobacterium, while MADBS enriched Ileibacterium, Muribaculaceae, and Dubosiella. The in vitro fermentation model demonstrated that WMS increased the abundance of Bifidobacterium, Lactobacillus, Megamonas, and Megasphaera, whereas MADBS enhanced Weissella, Lactobacillus, and Prevotella. Both compounds decreased the levels of Escherichia-Shigella. Metabolically, compared to the control group, WMS improved the production of acetic, propionic, butyric, and valproic acids, while MADBS decreased the concentrations of all short-chain fatty acids (SCFAs). Compared to the control group, WMS reduced the production of CH4, NH3, and H2S while increasing CO2 yield. MADBS reduced the generation of CH4, NH3, H2S, and CO2. These findings suggest that WMS and MADBS can modulate the gut ecosystem by selectively promoting probiotics, inhibiting pathogens, and altering metabolic profiles.