Journal of Advances in Microbiology

Cereal by-products, including bran, germ, husk, and brewer’s spent grain, are nutrient-rich residues produced during cereal processing. Traditionally considered waste or relegated to animal feed, these by-products have gained recognition for their valuable nutritional composition, containing dietary fibers, essential minerals (iron, zinc, copper, magnesium), B-complex vitamins, and bioactive compounds such as phenolics, lignans, and phytoestrogens. These constituents contribute significantly to human health by exhibiting antioxidant, anti-inflammatory, and cholesterol-lowering properties. Furthermore, cereal by-products present a promising low-cost substrate for microbial cultivation due to their abundance in complex carbohydrates, proteins, and fermentable sugars. Microorganisms such as lactic acid bacteria, yeasts, and fungi thrive on these substrates, facilitating the production of bioactive metabolites, enzymes, organic acids, and probiotics. Their use spans multiple sectors including food, agriculture, pharmaceuticals, and biofuels, aligning with the goals of sustainable development and circular economy. Valorization of cereal by-products not only reduces environmental pollution and agro-industrial waste but also enhances economic efficiency by opening new revenue avenues.  This review emphasizes the nutritional and functional properties of cereal by-products, their potential to support microbial growth, and their contribution to sustainable industrial innovations, while also highlighting the need for future research on formulation development and fermentation optimization.