News Notes

Microbiome of Horses With IBD Differs Greatly From Healthy Horses

Researchers at the University of Jyväskylä, Finland, are developing a promising method to support the diagnosis of inflammatory bowel diseases (IBD) in horses.

IBD is now a common disease in horses, causing serious welfare challenges such as diarrhea, weight loss, decreased performance and pain-related behaviors. Symptoms can lead to premature retirement and even euthanasia of the horse. IBD is usually diagnosed by observing general symptoms and then ultimately by endoscopy and examining a biopsy taken from the intestinal wall, the researchers said.

“Diagnosing IBD is also expensive for the owner and stressful for the horse, as it requires fasting, endoscopy and usually transportation to a horse hospital,” explained Academy Research Fellow Silva Uusi-Heikkilä, PhD, from Department of Biological and Environmental Science at the University of Jyväskylä, in Finland.

Furthermore, endoscopy is challenging because an adult horse has a long gastrointestinal tract and most of it remains unexplored during endoscopy for practical reasons.

Microbiota Composition Studied from Horse Fecal Samples
Researchers at the university explored the opportunities to use the composition of the bacterial community, or microbiota, in horse fecal samples as a non-invasive diagnostic tool for IBD. Studies in other species, such as humans, have shown that the gut microbiota composition can be used to detect IBD and the progression of the disease. Based on this knowledge, the researchers analyzed the microbiota composition of horse fecal samples to determine if they could indicate the presence of IBD.

They used 16S sequencing to compare the composition and diversity of the microbiome of 27 healthy horses and 49 horses diagnosed with IBD. They also measured a marker of intestinal inflammation called fecal calprotectin concentration in each group of horses.

They found the composition of the microbiota was different in the healthy horses than in the horses with IBD. However, less than 5% of the differences could be explained by health status and age, according to the researchers, who wrote: “Several differentially abundant bacterial taxa associated with IBD, age or body condition were depleted from the most dominant Firmicutes phylum and enriched with the Bacteroidota phylum.”

Dr. Uusi-Heikkilä explained, “We observed differences in the composition of the gut microbiota between horses with IBD and healthy horses. The relative abundances of certain bacterial groups were found to either increase or decrease in horses with IBD.”

Artificial Intelligence Utilized in the Research
Using microbiota composition assessments, the researchers developed a machine learning model to predict IBD based on the microbiota species composition in fecal samples. It was 100% accurate in predicting the samples from horses with IBD.

“This AI-based neural network model predicted IBD in the test samples with 100% accuracy,” said Postdoctoral Researcher Tiina Sävilammi from the University of Jyväskylä.

Benefits of the New Diagnostic Method for Humans and Animals
The researchers’ promising results suggest that in the future, analyzing the species composition of microbiota in fecal samples could become an accurate, cost-effective, and non-invasive method to support screening for IBD in horses. This advancement could reduce the stress and financial burden associated with current diagnostic methods, benefiting both horses and their owners.

The next step is to do more tests of the model and to improve its performance with more samples, Dr. Sävilammi said. MeV

For more information:
Sävilammi T, Alakangas RR, Häyrynen T, et al. Gut Microbiota Profiling as a Promising Tool to Detect Equine Inflammatory Bowel Disease (IBD). Animals. 2024;14(16): 2396 doe: 10.3390/ani14162396
https://www.mdpi.com/2076-2615/14/16/2396