Alterations in microbiota and fermentation products in equine large intestine in response to dietary variation and intestinal disease.

The study researched the effects of different diets on the gut bacteria and fermentation products in horses, shedding light on how diet adjustments can significantly impact the microbial ecosystems and their metabolites within the equine’s large intestine. Particularly, the research highlighted how these diet-induced changes may lead to common intestinal diseases in horses such as simple colonic obstruction and distension (SCOD).

Study Design and Methodology

• The researchers conducted their study on three groups of six horses each, each group maintained on different diets: a grass-only diet; a concentrate diet (supplemented with hydrolysable carbohydrates); and a concentrate diet in horses affected by SCOD.
• Oligonucleotide-RNA hybridization methodology was used to compare the bacterial communities within the large intestine of the horse groups under the different diets.

Pertinent Findings

• Changes to the diet or the presence of intestinal disease showed a progressive and significant increase in the population of certain bacteria. This includes Lachnospiraceae, Bacteroidetes assemblage, and the Bacillus-Lactobacillus-Streptococcus (BLS) group – known for its lactic acid production.
• Conversely, there was a decrease in the population count of certain bacteria responsible for breaking down fiber, specifically, Fibrobacter and Ruminococcaceae.
• Higher concentrations of lactic acid were observed in horses on a concentrate diet as well as those suffering from SCOD. This result lines up with the increased BLS group presence, a group of lactic acid-producing bacteria.

Insights and Implications

• The Veillonellaceae population, a group of bacteria that utilises lactic acid, remained constant regardless of the diet. The inability of this bacterial group to respond to increased lactic acid levels implies that this might be a contributing factor to the lactic acid build-up observed in horses on a concentrate diet or those suffering from SCOD.
• The study’s findings emphasize the impact of dietary changes on gut microbiota balance in horses, potentially leading to the development of common intestinal diseases like SCOD. This implies the need for careful diet management for horses to ensure their health and well-being.