【Abstract】 Objective To explore the effects of sialic acid intervention during pregnancy and lactational period on the intestinal function of autism model rats. Methods Thirty SPF-grade adult male and female Wistar rats were mated. The successfully pregnant rats were randomly assigned to valproate induced model group (VPA group), high dose sialic acid group (SAH group), medium dose sialic acid group (SAM group), low dose sialic acid group (SAL group) and control group (CON group) (n=6 per group) and were housed individually in single cages. On the 12.5th day of pregnancy, the pregnant rats in the VPA group and the SA intervention groups were given a single intraperitoneal injection of 600 mg/kg of sodium valproate (VPA), while the pregnant rats in the CON group were given an equal amount of normal saline. The SA intervention period was from E12.5 to the 21st day after the offspring born. Subsequently, the feces of the offspring rats in each group were collected. The diversity and structure of the gut microbiota were detected by 16S rRNA sequencing. The intestinal transit speed of the rats in each group was detected by intragastric administration of carmine. The expression levels of intestinal-related neurotransmitters (substance P, enkephalin, 5-hydroxytryptamine, vasoactive intestinal peptide, glutamate, gamma-aminobutyric acid) in the blood of the rats in each group were detected by the ELISA method. Results High-dose SA intervention did not affect the diversity of the gut microbiota in the VPA-induced autism model rats, but it changed the structure of the gut microbiota and increased the abundance levels of Prevotella_NK3B31 group, Prevotella, Prevotella spp., Alloprevotella, Lachnospira, Ruminococcus, Bacteroides, etc. (p < 0.05). It promoted the intestinal transit speed of the model rats. Moreover, it increased the levels of vasoactive intestinal peptide, 5-hydroxytryptamine, and gamma-aminobutyric acid in the serum of the rats. Conclusion SA intervention during pregnancy and lactational period affects the intestinal transit speed of VPA-induced autism model rats, changes the structure of the gut microbiome, and increases the expression levels of vasoactive intestinal peptide, 5-hydroxytryptamine, and gamma-aminobutyric acid.