Effect of body condition on intestinal permeability in horses.

This study was conducted to understand how a horse’s body condition affects the permeability of its intestinal mucosa. The researchers determined that obese horses may experience greater permeability of their intestinal mucosa, potentially exposing them to a higher risk from chronic exposure to lipopolysaccharides (LPS), compared to lean horses.

Study Methodology

• The research involved a total of thirteen horses, with seven being obese and the other six lean. The horses ranged from 8 to 15 years old.
• Each horse’s body condition score was assessed, and they were all subjected to an oral sugar test (OST) which evaluates the dynamics of glucose and insulin.
• After the horses were given a 2-week dietary acclimation period, they were euthanized for tissue sample collection.
• The team obtained tissue samples from various parts of the horses’ digestive system including the jejunum, ileum, cecum, pelvic flexure, right dorsal colon, and rectum.
• The permeability of the collected mucosal samples was assessed by measuring transepithelial resistance and LPS flux in Ussing chambers, a scientific instrument that allows measurement of the transport of ions across biological membranes.

Study Findings

• Five of the seven obese horses and one lean horse showed indications of insulin dysregulation. In contrast, one obese horse and five lean horses did not present any abnormalities in the OST.
• There was no significant difference in mucosal transepithelial resistance in any part of the intestine between the obese and lean horses.
• Obese horses, however, showed significantly higher LPS flux across the jejunal mucosa compared to lean horses. This difference was not observed in the other parts of the intestine.

Conclusions

• These results suggest that overweight horses may have greater paracellular (the space between cells) mucosal permeability of the jejunum to LPS compared to skinny horses.
• The findings align with previous studies on the gastrointestinal mucosa of humans and mice, supporting the hypothesis that obese horses could be more susceptible to chronic exposure to increased amounts of LPS compared to their lean counterparts.
• The implications of this research could help the veterinary community to better understand the potential risks associated with obesity in horses, and to develop appropriate care measures.