In a quest to gain insight into the function of the equine gastrointestinal tract (GI), Dr. Luis Arroyo and his team at the University of Guelph’s Ontario Veterinary College (OVC) are developing a glass gut model.

By simulating cecum and colon conditions using this in-vitro model, they plan to study microbiota (an ecosystem of microorganisms in the gut) and its crucial role in equine health. Once they establish what is “normal” in a healthy horse’s GI, long-term research could lead to an understanding of which disruptions to the microbiota lead to disorders such as colitis, laminitis and colic.

The glass gut model employs continuous microorganism systems, mimicking the nutritional and environmental conditions of the equine hind gut to achieve cultures of whole gut microbial communities. Researchers will be able to analyze microbial population compositions. “The first thing we want to know is how the gut flora of the horses normally behave in order to be able to build a well-established in-vitro model of the gut,” said Dr. Arroyo.

Samples have been collected from various parts of the intestinal tract of healthy horses to establish the glass gut so they can study and compare the genetic make up of their microbiomes: for example, comparing flora in the small intestine to that of the cecum. They have extracted DNA from these samples and are now moving into gene sequencing. The research will also compare gut contents from horses that have had colitis to a healthy control.

Dr. Arroyo and his co-investigator, Dr. Emma Allen-Vercoe from the Department of Molecular and Cellular Biology at the University of Guelph, will then extract fluid from the intestinal contents to see what metabolics have been produced in horses with and without colitis. This will provide important information for a well-established in-vitro model of a healthy gut. Dr. Allen-Vercoe recently developed an in-vitro human gut microbiota mixture of 33 isolates for the successful resolution of
C. difficile-associated diarrhea in human patients.

Although this project is designed to “get to know” what is normal in the gut, long-term benefits to the horse industry may result from flora disruption prevention strategies, and/or the development of products to counteract the damage to the resident gut flora.