Fecal transplantation has been very successful in treating humans with issues such as C-difficile infection, which is also a leading cause of diarrhea in horses. Ontario Veterinary College researcher, Dr. Luis Arroyo and his team are about to begin a study which could make treating gastro-intestinal (GI) issues in horses using fecal microbiota transplantation (FMT) a viable option. FMT has been given to horses with diarrhea, but so far, there is little evidence-based medicine to support that FMT is efficient in horses. One challenge is the path to the colon is much longer in a horse, precluding administration by enema for example, and therefore requiring delivery into the stomach via the nose instead. The inoculant needs to survive the trip to its intended destination. Another challenge is the preservation of a product that can be on hand when needed.
Amazing progress in genome sequencing has opened doors to new research tackling GI issues. Arroyo has been involved in studies examining the inhabitants of the equine gut and explains there is still much to learn, but we are starting to develop a clearer picture of how the micro-environments are very different in a diseased gut compared to a normal healthy one. They are recording what types of bacteria live in different areas of the GI system, what proportions of each bacteria should be present, and how they interact.
An altered composition of the intestinal bacteria is called dysbiosis and it is present in horses with intestinal diseases such as colitis and colic. Dysbiosis can also result during treatments involving antibiotics and it can take several weeks for gut microbiota to come back to normal.