Comparative Analysis of Intestinal Inflammation and Microbiota Dysbiosis of LPS-Challenged Piglets between Different Breeds

Simple Summary Post-weaning diarrhea is common in piglets, causing huge economic losses worldwide. The Heigai pig is an indigenous pig breed of China, and has lower rate of piglet diarrhea incidences than the Duroc × Landrace × Yorkshire (DLY) crossbred pig, which is the most widely used commercial pig crossbreed worldwide. In the current study, using lipopolysaccharide (LPS) as an agent to mimic the bacterial inflammatory response in weaned pigs, a comparative analysis of the effects of LPS challenge on jejunal mucosal morphology, jejunal microbial composition, and serum indexes in two pig breeds (DLY and Heigai) was performed. The results showed that LPS successfully induced bacterial inflammatory response in the experimental pigs, changed the microbial composition, and triggered functional changes in energy metabolism and activities related to the stress response in the jejunal bacterial community. This study also revealed that Heigai pigs had a weaker immune response to LPS challenge than DLY pigs, and identified several genera related to the breed-specific phenotypes of Heigai pigs. These findings provide a basis for investigating the mechanism of the intestinal inflammatory response in piglet diarrhea and suggest potential microbial candidates to resist diarrhea. Abstract Post-weaning diarrhea is common in piglets, causing huge economic losses worldwide. Associations between LPS challenge, intestinal inflammation, and microbiota have been reported in Duroc × Landrace × Yorkshire (DLY) crossbred pigs. However, the effects of LPS challenge in other breeds remain unclear. In the current study, we performed a comprehensive comparative analysis of the effects of LPS challenge on jejunal mucosal morphology, jejunal microbial composition, and serum indexes in two pig breeds: DLY and Heigai, an indigenous Chinese breed. The results showed that LPS caused considerable damage to the mucosal morphology, enhanced serum levels of inflammatory cytokines and the intestinal permeability index, and lowered the antioxidant capacity index. LPS challenge also changed the microbial composition and structure of the jejunum, significantly increased the abundances of Escherichia-Shigella in DLY pigs, and decreased those of Gemella and Saccharimonadales in Heigai pigs. Furthermore, LPS challenge triggered functional changes in energy metabolism and activities related to the stress response in the jejunal bacterial community, alleviating the inflammatory response in Heigai pigs. This study also revealed that Heigai pigs had a weaker immune response to LPS challenge than DLY pigs, and identified several genera related to the breed-specific phenotypes of Heigai pigs, including Gemella, Saccharimonadales, Clostridia_UCG_014, Terrisporobacter, and Dielma. Our collective findings uncovered differences between Heigai and DLY pigs in intestinal inflammation and microbiota dysbiosis induced by LPS challenge, providing a theoretical basis for unraveling the mechanism of intestinal inflammation in swine and proposing microbial candidates involved in the resistance to diarrhea in piglets.