Modulation of Gut Microbiota by Protein‐Oligosaccharide Maillard‐Reaction‐Derived Probiotic Microcapsules

ABSTRACT As a new type of prebiotic, the Maillard reaction products of protein ‐ oligosaccharide conjugates have emerged as a promising material for probiotic encapsulation and improve host health. However, the regulatory mechanisms of these conjugates on gut microbiota remain insufficiently explored. This study developed a probiotic microcapsule wall material through wet‐heating conjugation of soy protein isolate (SPI) and galactooligosaccharide (GOS). Lactobacillus acidophilus was successfully encapsulated using emulsification technology. Physicochemical characterization (pH, intermediate products, browning intensity, and glycation degree) validated the formation of SPI‐GOS conjugates. Subsequently, this study further investigated the impact of the Maillard‐reaction‐based microcapsule on human intestinal flora. The SGM microcapsule can significantly regulate the composition of intestinal flora. The in vitro digestion model demonstrated that the SGM microcapsules could increase the relative abundance of beneficial bacteria ( Bifidobacterium in Actinobacteriota and Prevotella in the Firmicutes ) and reduce the relative abundance of harmful bacteria ( Desulfovibrio and Escherichia‐Shigella in the Proteobacteria , Eggerthella , and Actinomyces in the Actinobacteriota ). Functional prediction analysis indicated that SGM microcapsules could improve the metabolic and biosynthetic functions of the intestinal microbiota. This Maillard‐derived SPI‐GOS microencapsulation system establishes a novel synbiotic paradigm synergistically combining prebiotic conjugates and probiotics. The findings provide guidance for developing functional foods targeting gut microbiota modulation, with significant implications for dietary intervention strategies in metabolic health management.