Cereal biomass-derived xylo- and malto-oligosaccharides as next-generation prebiotics: a comprehensive review of sustainable production and translational benefits for human and animal gut microbiota

Next-generation prebiotics are increasingly recognized for their ability to modulate gut microbiota and promote host health. Xylo-oligosaccharides (XOS) and malto-oligosaccharides (MOS), derived from cereal biomass, are particularly promising due to their structural stability, low effective dosages, and selective stimulation of beneficial gut microorganisms. This review synthesizes current knowledge on XOS and MOS, with emphasis on enzyme-enabled production technologies, microbial fermentation behavior, and health outcomes in humans and animals. Recent advances in tailored enzyme cocktails and sequential bioconversion strategies enable precise control over oligosaccharide yield and degree of polymerization, facilitating targeted production of functionally distinct fractions. Comparative analyses demonstrate that XOS and MOS offer greater microbial selectivity than conventional prebiotics, such as fructo- and galacto-oligosaccharides, and consistently enhance short-chain fatty acid production. These effects contribute to improved metabolic regulation, immune function, and resistance to enteric pathogens. A distinctive contribution of this review is the valorization of Kazakhstan's underutilized cereal residues, including wheat, rice, barley, and millet straw and bran, as sustainable feedstocks for prebiotic production. Integrating regional biomass with engineered enzyme systems provides a scalable and environmentally sound platform. Furthermore, combined XOS-MOS formulations may exert synergistic microbiota-modulating effects through complementary fermentation dynamics. Collectively, these insights position enzyme-based conversion of cereal biomass as a novel, regionally relevant strategy for advancing next-generation prebiotics.