Black corn (Zea mays L.) whole flour improved the antioxidant capacity and prevented adipogenesis in mice fed a high-fat diet

Black corn (Zea mays L.) flour has the potential to improve the gut microbiota composition and goblet cell proliferation in mice fed a high-fat diet

High-fat diets are associated with intestinal dysbiosis and leaky gut leading to intestinal inflammation. Bioactive components, including phenolic compounds, isolated or in their original food matrix, have alleviated intestinal impairments promoted by a high-fat diet. Black corn (Zea mays L.) is a colored corn in which anthocyanins are the most abundant bioactive compound. Thus, we hypothesized that black corn flour may have preventive effects on poor intestinal health in mice fed a high-fat diet. To study this, 30 C57BL/6 mice were randomly divided into 3 experimental groups receiving the following diets for 8 weeks: normal control (fed a normal diet); high-fat (fed a high-fat diet: 60% of calories from fat); high-fat corn (fed a high-fat diet added with 20% of black corn whole flour). The cecal microbiota analyzed by 16S ribosomal RNA sequencing showed that black corn flour intake increased the relative abundance of Ruminococcus, Roseburia, and Prevotellaceae_UCG-001, and decreased Bacteroides and Faecalibaculum. No difference was observed in the cecal short-chain fatty acids and fecal pH among the experimental groups (P > .05). Further, the consumption of black corn flour improved cecal morphology by increasing the number of goblet cells but with no difference in the crypt depth and width. These findings suggest that black corn flour as a source of anthocyanins could have preventive effects on gut dysbiosis resulting from a high-fat diet. SCFA, short chain fatty acids.

Effect of Black Corn Anthocyanin-Rich Extract (Zea mays L.) on Cecal Microbial Populations In Vivo (Gallus gallus)

Black corn has been attracting attention to investigate its biological properties due to its anthocyanin composition, mainly cyanidin-3-glucoside. Our study evaluated the effects of black corn extract (BCE) on intestinal morphology, gene expression, and the cecal microbiome. The BCE intra-amniotic administration was evaluated by an animal model in Gallus gallus. The eggs (n = 8 per group) were divided into: (1) no injection; (2) 18 MΩ H2O; (3) 5% black corn extract (BCE); and (4) 0.38% cyanidin-3-glucoside (C3G). A total of 1 mL of each component was injected intra-amniotic on day 17 of incubation. On day 21, the animals were euthanized after hatching, and the duodenum and cecum content were collected. The cecal microbiome changes were attributed to BCE administration, increasing the population of Bifidobacterium and Clostridium, and decreasing E. coli. The BCE did not change the gene expression of intestinal inflammation and functionality. The BCE administration maintained the villi height, Paneth cell number, and goblet cell diameter (in the villi and crypt), similar to the H2O injection but smaller than the C3G. Moreover, a positive correlation was observed between Bifidobacterium, Clostridium, E. coli, and villi GC diameter. The BCE promoted positive changes in the cecum microbiome and maintained intestinal morphology and functionality.