Effect of Millet Polyphenol-Rich Extracts on Human Fecal Bacteria and Dextran Sulfate Sodium-Induced Human Intestinal Epithelial Cell Derangements

There is a rejuvenated interest in functional food research on polyphenols due to their gut microbial modulation and capacity to alleviate clinical conditions. In this study, polyphenol-rich extracts (PREs) from Finger millet (FM) and Kodo millet (KM) were assessed for modulating effects on selected human gut bacteria during fecal batch fermentation along with the protective effects on Dextran Sulfate Sodium (DSS)-induced colonic aberrations in vitro. Fecal batch fermentation of FM-PRE and KM-PRE enhanced the abundance of selected beneficial bacteria, such as Bifidobacterium spp. Lactobacillus spp. and the production of SCFAs. Catechin and naringin were the main phenolic fractions of fermented FM-PRE and KM-PRE. Moreover, the millet polyphenols protected the intestinal cells against DSS-induced intestinal barrier dysfunction by reducing inflammatory cytokines, TEER by similar to 40%, FITC-dextran fluorescence and upregulating the expression of tight junction genes, signifying improved gut functions. The study also imply that FM and KM polyphenols may inhibit intestinal inflammation.