Lycium ruthenicum anthocyanins: Biosynthetic regulation and intestinal immunomodulatory effects along the gut immune axis

Lycium ruthenicum , a valuable medicinal and edible plant endemic to high-altitude areas in Northwest China, accumulates abundant anthocyanins, including the monomer petunidin-3- O -( trans - p -coumaroylrutinoside)-5- O -glucoside (PRG). Previous reviews on Lycium ruthenicum mainly cover its chemical components, bioactivities and industrial utilization; in contrast, this review delivers an in-depth, systematic overview. It takes genomic regulation of PRG biosynthesis, potential colonic availability inferred from in vitro digestion assays, and modulatory effects on intestinal immunity along the gut immune axis as the logical thread, delineating a coherent framework spanning structure, biological function, and mechanism of action. It first delineates the genomic and transcriptional regulation of PRG biosynthesis, laying a theoretical foundation for molecular breeding of cultivars with high PRG production. We elucidate the multilayered mechanisms by which PRG and Lycium ruthenicum anthocyanin crude extracts (LRA) modulate gut immune homeostasis: reshaping gut microbiota composition, enhancing intestinal barrier integrity, and balancing mucosal immunity. It then discusses the gut systemic regulatory effects of PRG on metabolic syndrome, colitis, and neuroinflammation, and clarifies the functional differences among them. Finally, it addresses the challenges in the clinical translation of PRG, including unclear pharmacokinetics, limited clinical evidence, and interindividual heterogeneity in gut microbiota composition and proposes a mechanistically grounded research agenda integrating multiomics, synthetic biology, and clinical trials stratified by microbiota profiles. Ultimately, this systematic review redefines LRA and PRG as promising nutritional intervention agents with potential colonic availability, and provides a theoretical framework and roadmap for their application in functional foods and adjuvant therapy for immunometabolic disorders.