Integrative microbiome-transcriptome analysis reveals immune activation linked to gut dysbiosis in Vespa magnifica

The gut microbiota plays a central role in the health of social wasps, contributing to nutrition, immunity, and environmental adaptation. However, its role in disease occurrence and host responses in the hornet Vespa magnifica remains poorly understood. Here, we investigated the gut microbial composition and host transcriptomic responses in diseased and healthy V. magnifica from Yunnan, China. High-throughput 16S rRNA gene sequencing revealed that diseased individuals exhibited significantly reduced microbial richness and diversity, characterized by depletion of beneficial taxa such as Lactobacillus (Lb.), Leuconostoc (Leu.), and Bifidobacterium (B.), alongside increased abundance of potential pathobionts including Lactococcus (Lc.) and Yokenella (Y.). Transcriptomic analysis identified 32 differentially expressed genes (DEGs), some of which were enriched for immune signaling pathways. Key immune-related genes, including peptidoglycan recognition proteins (PGRPs) and defensins (DEF), were strongly upregulated, indicating activation of host immune recognition and effector responses. Mantel correlation analysis further revealed significant associations between the top 30 differentially abundant bacterial genera and host immune genes, highlighting microbiota-host interactions in disease development. Collectively, these findings demonstrate that gut dysbiosis is associated with microbial imbalance and immune activation in V. magnifica, providing new insights into its gut health and potential strategies for disease management in hornet farming.