Mitigation of perfluorooctanoic acid immunotoxicity in Ruditapes philippinarum haemocytes by Lactobacillus plantarum Ps-8.

As an emerging pollutant, perfluorooctanoic acid (PFOA) poses potential risks to the immune systems of bivalves. While probiotic supplementation has been shown in aquaculture to mitigate pollutant-induced harm, its ability to modulate PFOA immunotoxicity in bivalves remains unclear. In this study, Ruditapes philippinarum was exposed to PFOA (0.2 or 20 μg/L) for six days, with or without dietary supplementation of the probiotic Lactiplantibacillus plantarum Ps-8 (10⁶ CFU/mL). Results indicated that L. plantarum Ps-8 reduced PFOA accumulation in the hemolymph. The probiotic also increased total haemocyte counts, enhanced cell viability and phagocytic activity, and decreased apoptosis and reactive oxygen species (ROS) levels. Furthermore, probiotic treatment improved haemocyte ultrastructure, elevated antioxidant enzyme activity, and lowered intracellular ROS. Downregulation of inflammatory response-related genes in haemocytes suggested that L. plantarum Ps-8 enhances immune function and alleviates PFOA-induced biotoxicity. This study comprehensively demonstrates the potential of L. plantarum Ps-8 to alleviate immunotoxicity in bivalve haemocytes, offering new insights for mitigating pollutant-induced biological damage.