Nutraceutical Potential of Fermented Finger Millet in Type 2 Diabetes Mellitus

Finger millet (FM; Eleusine coracana) has gained recognition as a potent dietary intervention for managing Type 2 diabetes mellitus (T2DM) due to its rich nutritional value and bioactive profile. This review focuses on the enhanced antidiabetic potential of fermented FM, emphasizing improvements in the bioavailability of these natural polyphenols and dietary fibers (DFs), via fermentation as well as the modulatory effects on gut microbiota. Finger millet (FM) is rich in complex carbohydrates-specifically dietary fibers like arabinoxylan and resistant starch-and phenolic compounds, such as ferulic acid, catechins, and tannins. These constituents provide antioxidant, anti-inflammatory, and glucose-regulating properties, which collectively contribute to its potent antidiabetic activity. Fermentation processes increase the release of bound phenolics and reduce antinutritional factors, such as phytic acid and tannins, via microbial enzymes, including feruloyl esterases and tannases, thereby enhancing mineral bioavailability and the efficacy of bioactive compounds. Additionally, fermentation enhances the growth of beneficial gut microorganisms, such as Lactobacillus and Bifidobacterium, which ferment fiber into short-chain fatty acids (SCFAs), such as butyrate and propionate. These SCFAs are crucial for enhancing glucose and lipid metabolism via pathways such as AMPK activation and GLUT4 translocation. In vivo studies reported that fermented FM products outperform non-fermented forms in lowering fasting blood glucose, improving lipid profiles, and protecting pancreatic beta-cell function, thereby substantiating their role as functional foods for T2DM management. These findings support the integration of fermented FM into dietary strategies aiming to mitigate diabetes and its complications, highlighting the importance of fermentation in unlocking its full nutraceutical potential.