Identification of Campylobactercoli as a key pathogen in Jinhua piglet diarrhea and its the probiotic control by Enterococcus faecium

The Jinhua piglets, a traditional breed prized for high-quality ham production, faces a critical challenge from post-weaning diarrhea. However, studies on diarrhea in Jinhua piglets are limited. Given the close link between diarrhea and the jejunal microbiota, this study analyzed the jejunal microbiota in diarrheic and healthy Jinhua piglets, and using a pseudo-germ-free (PGF) mouse model and in vivo/vitro approaches to investigate the causes of and potential interventions for diarrhea. Diarrheic Jinhua piglets exhibited altered microbiota diversity and composition of jejunal chyme, with significant enrichment of Campylobacter coli (C. coli), alongside impaired jejunal morphology, barrier function, and elevated IL-1β levels in jejunal mucosa. Transcriptomic analysis showed that immune system and immune disease pathways were enriched in jejunal mucosa of diarrheic Jinhua piglets, and transcription factors associated with inflammation showed a positive correlation with Campylobacter abundance. In PGF mouse model, oral gavage with either jejunal filtrate from diarrheic piglets or C. coli successfully recapitulated the damage of jejunal morphology and inflammation in jejunal mucosa. Enterococcus faecium (E. faecium) was identified in vitro for its ability to inhibit C. coli growth. Supplementing the diet with E. faecium notably lowered the occurrence of diarrhea, decreased the abundance of jejunal Campylobacter, and improved growth performance of piglets. This study identifies C. coli as a key pathogen contributing to diarrhea in Jinhua piglets, associated with diarrhea and jejunal inflammation, and highlights the potential of E. faecium as a probiotic strategy to control Campylobacter-associated diarrhea in this breed.