Supplementation of dietary heptadecanoic acid enhances anti-Listeria monocytogenes response in macrophages

Listeria monocytogenes infection often leads to listeriosis in immunocompromised individuals, and screening for potential nutrients that improve immunity may be beneficial. Here, we found that pre-incubation with heptadecanoic acid (C17:0), an odd-chain saturated fatty acid, significantly inhibited L.monocytogenes replication in differentiated THP-1 and RAW264.7, as evidenced by comparison of listeriolysin expression and colony count. Mechanistically, the administration of C17:0 triggered the activation of the IFN and NF-κB signaling pathways. Furthermore, C17:0 upregulated ACOD1 expression and the generation of itaconate, an anti-bacterial metabolite in macrophages. Based on these results, our comparative analysis showed that sheep tail fat (STF), ruminant lipid rich in C17:0, had similar anti- L.monocytogenes effect. Collectively, our data highlighted the function of C17:0 in boosting the immune response, shedding light on the application of C17:0 and STF as potential candidates for strengthening anti- L.monocytogenes response.