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Which? Prebiotic or Probiotic?

Many people use the terms prebiotic and probiotic interchangeably, but they are vastly different!


…are live cultures, usually of the lactobacillus or acidophilus families. Since probiotics are live cultures they begin to die as soon as they have been removed from the medium they are grown with. When you buy live cultures as a probiotic the bottle will tell you how many billion “colony forming units” are in the bottle or each dose. That’s true when the probiotic bottle is filled, unfortunately the moment the bottle is filled those colony’s begin to die, so expiration dates are particularly important with any live culture. Something else that affects the efficacy is approximately 90% of live cultures are killed in the acid bath of the stomach.

Another thing to consider is this: there are literally thousands of strains of microbes in a horses gut system, of those about 130 are important and roughly 30 are really important. Different strains of microbes digest the different nutrients we present to the horse; the reason we gradually change feeds is because new strains of microbes are needed to digest the new feed we present to the horse. So, how do you know the limited varieties of live cultures you are giving to your horse are what he or she needs to digest what it is being fed? You don’t and there is every possibility those microbes you are feeding, of which only 10% get through the acid bath of the stomach, are not the strains of microbes the horse is using to digest it’s food.

Have you ever heard someone say: “I give my horse a hot bran mash when it’s cold to help him warm up.” What happens is this…the horse doesn’t have the proper bacteria to digest the bran mash, so it slides right through the gut making a big mess on the floor or the walls of the stall. Horses heat themselves by eating forage which is fermented in the cecum which in turn gives off heat which warms the horse. That bran mash flushes everything out of the gut system so the horse has to start with forage again in order to start up it’s internal furnace. Not too smart in my book.


…are microbe food that feed whatever strains of microbes are doing the work of digesting the nutrients the horse is fed. Pretty simple, huh? So, instead of trying to figure out what strains of microbes are working in the horse’s gut to digest whatever nutrients it’s presented with, Forco just feeds the microbes doing the work. Way easier, straightforward and more effective than probiotics.

Note: If you are interested in what veterinary researchers have to say, I’ve included several links to articles you may find helpful. Caveat: Most publications don’t permit reuse of entire articles I’m citing here on commercial web sites so, instead, I’ve quoted some of the salient points presented in the articles.

Which? Prebiotic or Probiotic?


Several researchers found that, more often than not, the contents of probiotics were mislabeled and did not contain the concentration or the same organisms represented on the bottle. In at least one instance the contents were misspelled.

Several studies found the live organisms did not transit the stomach well. That’s a fancy way of saying the live cultures were killed in the stomach.

We really don’t know how many different species of bacteria are in either the human or horse gut. So how are we going to know what to put in there to help the horses digestion.

It appears it is preferable to feed prebiotics than probiotics. If you feel good feeding your horse probiotics, by all means continue, it probably won’t hurt them.

The first is a study done by Martin Furr, DVM, PhD, Dipl. ACVIM, a professor and Adelaide C. Riggs Chair in Equine Medicine at Virginia Tech’s Marion duPont Scott Equine Medical Center.

“In general, it appears that the available probiotic compounds are safe and unlikely to cause any problems; however, it remains unclear how useful they are overall. Further, the term ‘probiotic’ is very general, and there is likely to be a lot of difference between various products which use different organisms.”

“While scientific principles behind probiotics are sound, there are a number of problems with the practical use of such preparations. Every individual animal has a complex ecology of microbes colonizing it, and the specific type and number depend on species, environment, community, and individual genetics. Even for humans, as many as 80% of the organisms we harbor have yet to be identified or studied, and much less is known about the microbial ecology of companion animals. So trying to manipulate this ecology and the health of the individual by adding a few bacteria, often of a strain not naturally found in the individual, may not make sense. Also, numerous tests have shown that commercial probiotic products often do not contain the organism they claim, they are sometimes contaminated with undesirable organisms, and they may have too few microbes or non-living microbes in them. Without any formal government regulation or monitoring it is difficult to know whether individual products are safe or effective.”

All of the eight veterinary products examined contained <2% of the listed concentration of probiotic microorganisms.

Controlled studies in humans have been performed with enough regularity now to lend themselves to meta-analysis. Veterinary studies, on the other hand, are frustratingly sparse. Still, commercial preparations continue to manufacture probiotics with inconsistent standards of quality.”

In fact, Weese illustrated that out of 44 human or veterinary probiotics, organisms were improperly identified in 43% of human or 35% of veterinary samples and 25% of human or 18% of veterinary products had isolates that were even misspelled.

Further, Weese examined 13 veterinary or human probiotics in the laboratory and found label description and concentrations were accurately stated in only 2 products, neither was a veterinary product.”

Therefore, it appears that probiotics have limited benefits to horses, and may even be harmful in some cases. Even fewer studies have been conducted on prebiotics in horses, though one study reported fewer digestive disruptions upon a sudden dietary change when horses were fed a prebiotic compound, short chain fructo-oligossacharide.

In addition to the scant amount of scientific evidence of efficacy in equines, horse owners should be aware that all commercially available products are not created equal. In fact, a study conducted by Dr. Scott Weese, DVM, DVSc, Dipl ACVIM, of the University of Guelph, found that only two of 13 commercial products tested actually contained the types and amounts of organisms as labeled on the packaging. It is possible that the shelf-life of some of these products may be limited to ensure viable microbes upon use. Therefore, even if health benefits were expected, there appears to be little quality control or regulation regarding the manufacturing of such products. Horse owners are advised to research and contact companies regarding their products and ask for documentation concerning the product’s composition, safety and efficacy.

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