Gut microbiota-derived 3-indoleacrylic acid mediates ferulic acid protection against aflatoxin B1 hepatotoxicity via AhR-ferroptosis inhibition in animals

Aflatoxin B1 (AFB1) contamination is a persistent threat to feed safety and animal production due to potent hepatotoxicity. Although cereal-derived bioactive compounds are promising interventions against AFB1-induced liver injury, their microbiome-dependent protective mechanisms remain poorly understood. Here, we aimed to determine whether the cereal-derived polyphenol ferulic acid (FA) alleviates AFB1-induced liver injury in ducks in a gut microbiota-dependent manner, elucidating the underlying mechanisms. The results show that FA exerts gut microbiota-dependent hepatoprotection, evidenced by antibiotic treatment and fecal microbiota transplantation in ducks. Specifically, dietary FA enriches Peptostreptococcus anaerobius , enhancing microbial conversion of tryptophan to 3-indoleacrylic acid in vivo and in vitro. Combining single-cell RNA sequencing and surface plasmon resonance, we demonstrate that 3-indoleacrylic acid functionally antagonizes AFB1-induced hyperactivation of the AhR pathway, thereby suppressing AhR-driven ferroptosis. This function has been validated through genetic knockdown and pharmacological interventions. Crucially, we reveal that 3-indoleacrylic acid ameliorates AFB1-induced liver inflammation by reprogramming macrophage subset composition and function. Collectively, our findings unveil a molecular mechanism of host-microbe crosstalk, identifying the Peptostreptococcus anaerobius -derived metabolite 3-indoleacrylic acid as a critical signaling mediator that inhibits AFB1-induced hepatic AhR hyperactivation, ferroptosis, and macrophage reprogramming. This work provides a rationale for microbiome-targeted feed strategies to combat aflatoxicosis and improve animal health.