Clostridium perfringens can promote the formation of fatty liver in cows.

During the periparturient period, reduced feed intake often causes negative energy balance in dairy cows, leading to fat mobilization, hepatic lipid accumulation, and fatty liver disease (FLD), ultimately compromising health and milk production. This study investigated the association between FLD and gut microbiota dysbiosis, with a particular focus on the role of Clostridium perfringens within the gut-liver axis. Metagenomic sequencing of ileal contents revealed a marked decrease in microbial diversity in cows with FLD, along with increased abundances of potential pathogens such as C. perfringens, Enterobacter cloacae, and Vibrio alginolyticus. Functional annotation indicated elevated expression of virulence factors (e.g., Hsp60, flagella, mu-toxin), antibiotic resistance genes (e.g., otrA, lsaC), and pathways related to lipopolysaccharide (LPS) biosynthesis and mitogen-activated protein kinase (MAPK) signaling pathways, suggesting enhanced pro-inflammatory potential. qPCR analysis of ileal tissue demonstrated reduced expression of tight junction proteins (zona occludens 1 (ZO-1), Claudin-1, and Occludin) and increased levels of pro-inflammatory cytokines (Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), Tumour necrosis factor-alpha (TNF-α)), alongside a decrease in the anti-inflammatory cytokine interleukin-10 (IL-10), indicating compromised intestinal barrier function and local inflammation. Given the significant enrichment of C. perfringens in the ileum of FLD cows, we hypothesized its involvement in disease pathogenesis. To test this, C. perfringens was isolated and orally administered to antibiotic-pretreated mice fed a high-fat diet. These mice developed exacerbated hepatic steatosis, metabolic disturbances, and heightened inflammatory responses. Moreover, Western blot analysis revealed reduced expression of intestinal tight junction proteins (ZO-1, Claudin-1, Occludin), indicating increased intestinal permeability. Quantitative PCR confirmed upregulation of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and downregulation of IL-10 in both intestinal and hepatic tissues. These findings indicate that C. perfringens may promote FLD by impairing gut barrier integrity and enhancing inflammatory responses. In conclusion, our findings suggest that C. perfringens may contribute to the development of FLD in dairy cows by impairing intestinal barrier integrity and promoting systemic inflammation.