Acute Toxoplasma gondii Infection Drives Gut Microbiome Dysbiosis and Functional Disruption in Mice as Revealed by Metagenomic Sequencing

<i>Toxoplasma gondii</i> is a widely distributed intracellular parasite that disrupts host immune and metabolic homeostasis. Although accumulating evidence highlights the role of gut microbiota in parasitic infections, the effects of acute <i>T. gondii</i> infection on host gut microbial ecology remain poorly understood. In this study, metagenomic sequencing technology was used to systematically analyze the composition and functional alterations of the ileal microbiota in BALB/c mice on day 10 post-infection. Compared to uninfected controls, <i>T</i>. <i>gondii</i> infected mice exhibited a significant reduction in microbial diversity and a pronounced shift in community structure. Notably, there was an expansion of Proteobacteria, particularly the Enterobacteriaceae family, alongside a marked decline in beneficial taxa such as Actinobacteria and Bacillota. Functional annotation using the KEGG and CAZy databases revealed enrichment of metabolic pathways related to glycolysis/gluconeogenesis, O-antigen nucleotide sugar biosynthesis, bacterial secretion systems, and biofilm formation-<i>Escherichia coli</i> in the infected microbiota. These findings provide novel insights into the dysbiosis of gut microbiota and host-microbe interactions during acute <i>T. gondii</i> infection.