Cyanidin-3-O-glucoside alleviates aflatoxin B1-induced splenic immunotoxicity via gut microbiota remodeling.

While the hepatotoxicity of aflatoxin B1 (AFB1) is well characterized, its immunotoxicity remains overlooked. This study investigates whether cyanidin-3-O-glucoside (C3G), a bioactive polyphenolic flavonoid, can alleviate AFB1-induced immunotoxicity. Our results demonstrated that C3G significantly ameliorated AFB1-induced splenic injury, which was associated with the suppression of the NLRP3/caspase-1/GSDMD pyroptosis pathway and reduced expression of IL-1β and IL-18. Furthermore, C3G modulated the gut microbiota by enriching specific beneficial bacteria (e.g., Alistipes and Candidatus Saccharimonas) and reversed AFB1-induced metabolic disorders. Transplantation of fecal microbiota from C3G-pretreated donor mice reproduced the protective effect of C3G in mice exposed to AFB1, whereas sterile fecal filtrate transplantation only offered partial relief, indicating that the core mechanism depends on viable microbiota. In summary, C3G alleviates AFB1-induced splenic injury by restructuring the dysbiotic gut microbiota into a more enriched community. This remodeling restores metabolic homeostasis and inhibits NLRP3-mediated pyroptosis via the gut-spleen axis. Our findings demonstrate that C3G alleviates AFB1-induced splenic immunotoxicity by remodeling the gut microbiota via the gut-spleen axis, establishing a novel microbiota-dependent strategy mediated by natural polyphenols.