Changes of microbial and metabolome of the equine hindgut during oligofructose-induced laminitis

Laminitis is a common and serve disease which caused by inflammation and pathological changes of the laminar junction. However, the pathologic mechanism remains unclear. In this study we aimed to investigate changes of the gut microbiota and metabolomics in oligofructose-induced laminitis of horses.

Animals submitted to treatment with oligofructose had lower fecal pH but higher lactic acid, histamine, and Lipopolysaccharide (LPS) in serum. Meanwhile, oligofructose altered composition of the hindgut bacterial community, demonstrated by increasing relative abundance of Lactobacillus and Megasphaera. In addition, the metabolome analysis revealed that treatment with oligofructose decreased 84 metabolites while 53 metabolites increased, such as dihydrothymine, N3,N4-Dimethyl-L-arginine, 10E,12Z-Octadecadienoic acid, and asparagine. Pathway analysis revealed that aldosterone synthesis and secretion, regulation of lipolysis in adipocytes, steroid hormone biosynthesis, pyrimidine metabolism, biosynthesis of unsaturated fatty acids, and galactose metabolism were significantly different between healthy and laminitis horses. Furthermore, correlation analysis between gut microbiota and metabolites indicated that Lactobacillus and/or Megasphaera were positively associated with the dihydrothymine, N3,N4-Dimethyl-L-arginine, 10E,12Z-Octadecadienoic acid, and asparagine.

These results revealed that disturbance of gut microbiota and changes of metabolites were occurred during the development of equine laminitis, and these results may provide novel insights to detect biomarkers for a better understanding of the potential mechanism and prevention strategies for laminitis in horses.