Dietary supplementation of micro-encapsulated sodium butyrate in healthy horses: effect on gut histology and immunohistochemistry parameters

Abstract

Abstract Background As colic and intestinal disorders are a major concern in horses, the aim of the present study was to investigate the effect of dietary supplementation of butyrate, known to have a diverse array of beneficial effects on intestinal health. The effect of micro-encapsulated sodium butyrate supplementation on gut histology and immunohistochemistry parameters was studied in 14 healthy warmblood horses destined for slaughter in two separate periods. Horses were fed a low fiber - high starch diet, designed to induce subsequent starch overflow in the large intestine, aiming to create a mild challenge for large intestinal health. Treatment included supplementation with either micro-encapsulated sodium butyrate (Excential Butycoat®, Orffa, Werkendam, the Netherlands) or placebo (containing only coating material). The horses were fed for 20 consecutive days at a dosage of 0.4 g/kg BW (body weight). At day 21, the horses were slaughtered and intestinal samples were collected for determination of gut pH, villus length, crypt depth and area % of CD3+ and CD20+ cells. Results Horses on the butyrate supplemented diet had significantly reduced crypt depths in the right dorsal colon compared to placebo-fed horses (P < 0.001). However, a treatment x period interaction (P = 0.002) was discovered regarding this parameter, which could not be explained by the authors. Further investigation into the number of KI67+ cells in the RDC crypts did not reveal any significant differences between treatments (P = 0.650), indicating that the reduction in crypt depth in butyrate-fed horses could not be explained by a significant difference in cellular proliferation. Intestinal pH, villus length and expression of intestinal CD3+ and CD20+ cells were not significantly affected by treatment at any intestinal level. Conclusions Our data indicate that supplementation of micro-encapsulated sodium butyrate to the equine diet did not influence gut histology (with the exception of a decrease found in the crypts of the RDC) or immunohistochemistry parameters in healthy horses. Further research is warranted to investigate the impact of butyrate supplementation in horses with intestinal disease.

Keywords

• Butyrate
• Diet
• Equine
• Histology
• Immunohistochemistry