Baicalin alleviates summer heat stress in lactating sows through coordinated modulation of gut microbiota metabolite host axis

Heat stress during lactation markedly compromises sow productivity by inducing systemic inflammation and metabolic dysregulation, while conventional physical cooling strategies are often insufficient. This study evaluated whether dietary supplementation with baicalin, a flavone-derived phytochemical from Scutellaria baicalensis, could alleviate heat stress associated disturbances in lactating sows through modulation of the gut microbiota host metabolic axis. Supplementation with 0.06% baicalin significantly reduced rectal temperature and circulating stress indicators, including cortisol and heat shock protein 70, while attenuating pro inflammatory cytokine levels. Concurrently, feed intake, milk yield, and litter weaning weight were significantly improved. Gut microbiota profiling revealed increased microbial diversity and enrichment of beneficial taxa, particularly Lactobacillus, accompanied by elevated fecal concentrations of propionate and butyrate. Untargeted metabolomic analysis indicated partial restoration of glycolipid metabolism, steroid hormone biosynthesis, and bile acid related pathways, with glucose-6-phosphate emerging as a central metabolic hub. Network analysis further suggested coordinated interactions among Lactobacillus, Euryarchaeota, and glucose-6-phosphate that were associated with improved metabolic homeostasis. In addition, maternal baicalin supplementation altered the gut microbial composition of offspring, as reflected by an increased Firmicutes to Bacteroidetes ratio. Collectively, these findings demonstrate that baicalin supplementation is associated with improved thermal resilience and metabolic stability in lactating sows, likely through coordinated microbiota metabolite host interactions, supporting its potential application as a microbiome targeted dietary phytochemical in swine production systems.