From the 2022 Kemin Intestinal Health Symposium
By Ann Hess When Tania Cubitt discusses the equine microbiome with her clients, she relates it to being another organ in the horse’s body. “It has so much control and in the horse a lot of different factors can affect that microbiome. Did I change the feed? Did the weather outside change? How much you exercise the horse, trailering the horse, the different disease states can also change that micro population,” said Cubitt, a nutritionist with Performance Horse Nutrition. “Even just domesticating horses and changing the management has significantly decreased their kind of microbial diversity.” During the recent Kemin Intestinal Health Symposium in Palm Springs, California, Cubitt described the equine microbiome as a “gastrointestinal puzzle,” and examined the opportunities for pre-, pro- and postbiotics in equine diets. Most horses are fed one of three diets: high fiber, high fat or high starch, and as an equine nutritionist, Cubitt says she doesn’t have much say in getting an owner to change the diet to one of the other three. “I can't tell a person that is about racehorses and racing in the Kentucky Derby to stop feeding sugars and starches to their horses because then they'll just be really slow,” Cubitt said. “But I think the goal of what I try to do is understanding the normal management that we do with horses and what negative impacts that has on them, and then how we can mediate that with potentially some other maybe pro-, pre- or postbiotics.”
Check out our interview with Tania Cubitt. She lends her insights from the world of performance horse nutrition to helping livestock producers better understand the way pre, pro, and postbiotic products might help unlock improved intestinal health and productivity in their animals.
Instead, Cubitt centers on precision feeding strategies, with a focus on feeding the microbiome as the gut microbiome is the link between nutrition and health. With so many stressors facing equine on a daily basis, from the diet and environment to transportation and performance, Cubitt said the horse’s diet is an area she focuses on to mitigate some of those stresses through prebiotics, probiotics and postbiotics. Prebiotics are specialized fibers, complex carbohydrates or substrates that act as food or energy for beneficial micro-organisms in the gut. Typical products used in the equine industry are mannan oligosaccharide (MOS), fructo oligosaccharides (FOS), beet pulp, oat hulls, soy hulls and beta-glucan. Probiotics provide supplemental beneficial micro-organisms in the gut and must be alive to work. Bacteria such as Lactobacillus acidophilus, Streptococcus faecium and Bacillus subtilis; fungi like Aspergillus oryzae and yeast strains of the Saccharomyces species are commonly used in horse diets. Prebiotics feed the beneficial microbes, while probiotics increase the population. The beneficial microbes then improve digestion and absorption of fiber and other nutrients, produce beneficial metabolites that impact the immune, nervous and endocrine systems, and help prevent the growth of harmful microbes. Postbiotics, formed after the metabolism of prebiotic compounds by the gut microbes, are defined as beneficial substances, resulting from microbiota metabolism and having a beneficial effect on the microbiota itself as well as the host. A recent study recognized over 1,300 unique metabolites are produced by the equine microbiome. The problem Cubitt’s clients often have is figuring out what product to choose, with many turning to social media, internet searches and the latest trends surrounding human nutrition. “By definition horses are livestock, but they're not. They're companion animals. I've been into plenty of barns that are way nicer than the house next door. People spend a lot of money on their horses because they're part of the family and they have emotions,” Cubitt said. “Whatever trend is happening in the human food industry seems to trickle down. I constantly get questions, ‘well, I read this on the internet, and I thought I should try it with my horse.’” With performance and return on investment coming down to the individual horse owner, Cubitt tries to help clients pick products by first examining if there has been any research on the product and is it safe for all classes of horses. Can it be pelleted? What’s the processing, packaging and shelf life? Finally, does the product play nice with others? “I think that we are using a combination of pre- and probiotics, but I'd love to see pre-, pro- and postbiotics all come together and more research on which ones are actually going to work well together to be better than their individual parts,” Cubitt said. While the bare minimum for nutrients requirements for horses is to avoid sickness and disease, Cubitt believes the industry could do a better job understanding the microbes in the equine gut. “I think we need to understand more about different disease states, different stresses we're putting on these horses and how that's changing the gut, changing the gut microbiome and then target those particular microbes,” Cubitt said. “And then research, does it work? A lot of times it will work in a lab that's great, but then when you're in the field and the product set on the shelf, or you live in Florida and it's been in the barn, it's been really hot and it's all cooked, or you live in Wisconsin and it's frozen. We need to make sure that we're actually not just looking at what's working in a lab, but what's working in the field as well.” For example, several studies have shown the use of probiotics increased the risk of diarrhea in neonatal foals. However, Cubitt said the probiotic wasn’t “bad,” it was used incorrectly. Also, what works for a young horse may not work for a senior, and what works for a horse that has undergone trailering stress may not work for a horse that’s undergone colic surgery. Cubitt said another issue for the equine industry is the fact that there's really not a lot of regulation on these products. She references a recent study where a total of 54 products were identified claiming to contain live microorganisms. A random number generator was used to select 11 of these products. The products were stored according to the manufacturers’ recommendations. They also simulated acidity and the normal conditions in the gut. None of the products actually met that label claim. “And it wasn't the first study that had shown this over the last 20 years. Sixteen other supplements had been tested in a couple of other studies and none of them met the label plan, so it's not a new issue,” Cubitt said. "If we overcome that and we actually can do a little bit more research on making sure that these products are withstanding, handling shelf life, because they also made sure they handled the products at the manufacturers’ directions. Some of them didn't even have directions on how to store the products and none of them had an expiration date.” Another term often used in equine nutrition is synbiotics. Initially conceived as a combination of both probiotics and prebiotics, a synbiotic has now been defined as “a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host.” “I think that again, in the equine world, selecting correctly the right types of prebiotics that are going to work best for those probiotics, that it will work in the right situation,” Cubitt said.
Finally, it comes back to what is the goal for that particular horse. “Are we just trying to avoid them getting sick or is it I'm working with a vet hospital and the horses have all undergone severe stress, whether it be from surgery or using antimicrobials or is it a certain disease?” Cubitt said. “Do these horses have metabolic syndrome, are obese and have things like laminitis? What is the goal? What am I trying to overcome to improve the health of the hind gut? And are we altering the gut environment to support the transition of those biotics to the areas where they need to be utilized?” When choosing a product for her clients, Cubitt scrutinizes the companies/products for the following attributes: • Products with quality control and research which supports both the type and quantity of microorganisms present within the product. • Research demonstrating that they provide a benefit to the horse and are safe to use. • Companies marketing “biotics” should be held accountable for label claims and should support high quality equine research and rigorous product development. • No one stop solution, not singular. • Holistic approach.
“I can get really focused on just looking at this prebiotic or that probiotic or this part of the gut, but I think, especially in horses, you've got to step back and it's not one solution. It's not singular,” Cubitt said.