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.