Gut Microbiota Modulation by Dietary Barley Malt Melanoidins

Melanoidins are the final Maillard reaction products (protein-carbohydrate complexes) produced in food by prolonged and intense heating. We assessed the impact of the consumption of melanoidins from barley malts on gut microbiota. Seventy-five mice were assigned into five groups, where the control group consumed a non-melanoidin malt diet, and other groups received melanoidin-rich malts in increments of 25% up to 100% melanoidin malts. Feces were sampled at days 0, 1, 2, 3, 7, 14, and 21 and the microbiota was determined using V4 bacterial 16S rRNA amplicon sequencing and short-chain fatty acids (SCFA) by gas chromatography. Increased melanoidins was found to result in significantly divergent gut microbiota profiles and supported sustained SCFA production. The relative abundance of , , and were decreased, while , , , , and increased. spp. and spp. were significantly increased in mice consuming the highest melanoidin amounts, suggesting remarkable prebiotic potential.