Abstract: Objective  To investigate the effect of probiotics on febrile seizures (FS) in rats and NOD-like receptor pyrin domain-containing protein 3(NLRP3) inflammasome activation in hippocampus. Methods  A total of 120 rats were randomly divided into three groups: a control group, a model group, and a probiotic treatment group, with 40 rats in each group. FS rat models were established in both the model group and the probiotic group. The probiotic group was administered with microecological preparations via gavage, while the model group and the control group were fed with distilled water. After the intervention, the model group and the probiotic group were subjected to a hot water bath stimulus again to induce a secondary FS episode. Relevant indicators were recorded, and samples were collected for detection and analysis. Results  For the blank group, the structure of neurons in hippocampus was complete, the morphology was regular, and the size is uniform. For the model group, hippocampal zones varied in width, cell number in hippocampus decreased, and the arrangement of hippocampal neurons was irregular. For the probiotics group, cell number in hippocampus were more than the model group, and the changes in the structure were fewer than those in the model group. Compared with the model group, the latent time of FS was significantly longer, the duration of FS was significantly shorter, and the level of FS was significantly lower in the probiotics group (P<0.05). The relative expression levels of NLRP3, interleukin-1β(IL-1β), and interleukin-18 (IL-18) proteins in hippocampal tissues and serum of the probiotic group were significantly fewer than those in the model group but significantly higher than those in the control group, with statistically significant differences between groups (P<0.05). The numbers of Bifidobacterium and Lactobacillus decreased sequentially from the control group to the probiotic group and then to the model group, while the numbers of Escherichia coli and Enterococcus faecalis increased correspondingly, with statistically significant differences between groups (P<0.05). The levels of dia mine oxidase (DAO), D-lactate, and NO in serum of the probiotic group were lower than those in the model group but higher than those in the control group, with statistically significant differences between groups (P<0.05). Conclusion  Probioticseffectively alleviate FS episodes by inhibiting NLRP3 inflammasome activation, reducing inflammatory cytokine levels, modulating intestinal microbiota composition, and preserving intestinal barrier function, providing a novel strategy for the prevention and treatment of FS.

Key words: probiotics, fever seizures, rat, hippocampus, NOD-like receptor pyrin domain-containing protein 3, inflammasome