Innovative Oat‐Based Postbiotic and Synbiotic Products: Chemical Constituents and Hepatoprotective Efficacy

ABSTRACT Oat ( Avena sativa ) is a health‐promoting food exhibiting prebiotic properties. We invented oat‐based postbiotics (Oat_PB) fermented with probiotics (mainly Lactobacillus and Bifidobacterium ) and comprehensively compared their chemical constitutions with the synbiotic form (Oat_SB). Oat_PB accumulated β ‐glucan, avenanthramides (2c, 2p, and 2f) as well as free amino acids, for example, threonine, valine, arginine, aspartate, citrulline, and taurine, while reducing total phenol, flavone, and protein. Oat_PB enriched metabolites affecting lipid and glucose metabolism. Probiotics‐derived oat foods mitigated high‐sucrose‐induced obesity, liver injury, and repaired lipid and glucose metabolism in rats, with Oat_PB showing most pronounced effects. Oat_PB reversed high‐sucrose disturbed hepatic fatty acid profiles, and regulated genes and proteins involved in lipid homeostasis. Oat_PB ameliorated gut dysbacteriosis by increasing Alloprevotella , Prevotella , and Akkermansia while inhibiting harmful bacteria. Collectively, our study demonstrates the additional value of probiotic‐derived oat foods beyond the raw oat materials in preventing metabolic homeostasis and gut dysbacteriosis.