Luminal and Mucosal Microbiota of the Cecum and Large Colon of Healthy and Diarrheic Horses

Abstract

The aim of this study was to compare the mucosal and luminal content microbiota of the cecum and colon of healthy and diarrheic horses. Marked differences in the richness and in the community composition between the mucosal and luminal microbiota of the cecum and large colon of horses with colitis were observed. Microbial dysbiosis occurs in horses with colitis at different levels of the intestinal tract, and microbiota composition is different between the mucosa and luminal content of diarrheic horses. The changes in some key taxa associated with dysbiosis in the equine intestinal microbiota, such as Escherichia, Fusobacterium and Lactobacillus, deserve further inquiry in order to determine their utility for disease diagnosis and treatment.

Keywords: diarrhea; equine colitis; intestinal microbiota.

Figure 1

Richness indicated by the number of observed genera found in the mucosal (blue) and luminal content (red) microbiota of healthy horses and horses with colitis, demonstrating statistically higher richness in lumen compared to mucosa of diarrheic horses. * Statistical significant different between groups.

Figure 2

Principal coordinate analysis (PCoA) illustrating similarities in community composition of bacteria present in the lumen and content of the cecum (A) and colon (B) of healthy (CON) horses and horses with colitis (COL).

Figure 3

Relative abundances of the main bacterial genera (>1% of total reads) present in the cecum and colon of healthy horses and horses with colitis.

Figure 4

LEfSe analysis representing bacterial taxa statistically associated (LDA score > 4) with samples obtained from healthy horses (green) or horses with colitis (red).