Probiotics, prebiotics and postbiotics

First of all, I’m often asked this question:

Saccharomyces products – which one do I feed?

Do Mycosorb A+ and Postbiotic Gut Support (TruEquine C Ultra/Diamond V XPC Ultra), do the same job?
Note: Diamond V is now called TruEquine C.

Mycosorb A+ is a fungal toxin binder and Postbiotic Gut Support is a postbiotic to support robust gut function (microbial fermentation). Do you need any of these?

First of all, what is Saccharomyces cerevisiae?

Saccharomyces cerevisiae is a single-celled eukaryote (yeast/fungi – brewers yeast) that is frequently used in scientific research and has many applications. The advantages are that its genome has been sequenced, its genetics are easily manipulated, and it is very easy to maintain in a lab. Historically it was mainly used in the production of food and winemaking and is believed to have been originally isolated from the skin of grapes. Studies with S. cerevisiae have contributed to our understanding of important cellular processes such as the cell cycle, aging, and cell death, protein purification and the study of DNA repair mechanisms and other cellular processes related to Alzheimer’s and Parkinson’s diseases.

I’m not sure of the exact number but there are so many products that are made from Saccharomyces cerevisiae and they all have different jobs, as they are different strains. The difference can come from the different substrates for the fermentation by S. cerevisiae, what these ‘critters’ are fed. Some are patented like Postbiotic Gut Support (TruEquine) and Mycosorb A+ (Alltech Inc). Postbiotic Gut Support is a postbiotic which means it contains the beneficial metabolites released from gut bacteria when they feed on fibre. Another way of saying this is that postbiotics are formed through fermentation. Postbiotics can help prevent infections, reduce inflammation and strenthen the immune system. Not to be confused with probiotics or prebiotics.

To summarise:
Probiotic = live bacteria, products contain a small, select number of species with a number of individuals measured in colony forming units (CFU). These are a small number of specific microbial species to add to the populations of these species in the horse’s gut. Can be limiting as often the CFU is not high enough to be significant, and not a broad range of species.  

Prebiotic = food sources for gut bacteria, will include any feed ingredient that bacteria can ferment; including grass, hay, high fibre feeds like beet pulp, soybean hulls and lupin hulls. Prebiotics support gut populations.

Postbiotic = inanimate microbes and their beneficial metabolites or substances released from the fermentation process by gut bacteria. These support digestive and immune functions, as well as nurture the gut microbiome and help it flourish.

Mycosorb A+ is a fungal toxin binder. These two products, even though it’s the same species of yeast, are not the same as they are different patented strains.

The Medina et al study showed that S. cerevisiae strain/preparation helped prevent colonic acidosis in horses on crazy high grain diets. The Newbold et al study on S. cerevisiae showed how different strains were effective for sheep. Links at the bottom of the page.

Elitox, the other toxin binder in the shop is not a S. cerevisiae product.  Read about toxin binders and how they differ.

So to sum up, the different strain or type of S. cerevisiae product can have different jobs/activities.

Do you need these products

Yes to Mycosorb A+ (or Elitox) if you are concerned about your hay being mouldy or are experiencing a fungus outbreak in your pasture, for example, Paspalum ergot fungus or certain strains of endophyte perennial ryegrass and tall fescue, consider a toxin binder. These plants and others are renowned for causing photosynthesisation, signs are sunburn and blistering on pink skin on faces and pasterns (generic term, greasy heel or mud fever). When an animal consumes a plant or chemical containing these pigments (eg. polyphenolic), the pigments circulate to the skin where they are exposed to UV light, fluoresce and cause oxidative injury to the cells of the skin. Liver damage in a horse might not be noticed until the animal develops photosensitisation.

There are other types of toxin binders available with disadvantages which you can read about in the toxin binders article.

Mycosorb A+
Mycosorb A+

Postbiotic Gut Support is a postbiotic, containing hundreds of beneficial metabolites that support many digestive and immune functions. If your horse is exhibiting a hay or grass belly OR have a degree of diarrhoea then Postbiotic Gut Support may well help. The XPC Ultra means it’s 8x more concentrated than Diamond V. Best to consult your vet as there are veterinary conditions that cause diarrhoea.

What is brewer’s yeast?

Brewer’s yeast, what you can often buy cheaply at stockfeed suppliers is known as ‘spent’ S. cerevisiae. When sold as a dietary supplement it is typically spent/dead and fed primarily for B vitamins.

Note: If your horse has robust gut function and is not on a crazy high grain intake then probably not necessary to consider B vitamin supplementation as horses gain B vitamins from what they eat (grass/hay) and gut microbes produce all the B vitamins. The best source is green grass.

Postbiotic Gut Support

If you think your horse needs more biotin, Balanced Equine has biotin in the HoofXtra mix and the high concentrated single ingredient Balanced Equine 2% Biotin.

Further reading:

Some examples of research.
Links may change over time. If a link doesn’t work, search the title in your search engine.

Coverdale JA (2016) Horse Species Symposium: Can the microbiome of the horse be altered to improve digestion? J. Anim. Sci. Jun;94(6):2275-2281

Medina B, Girard ID, Jacotot E and Julliand V (2002) Effect of a preparation of Saccharomyces cerevisiae on microbial profiles and fermentation patterns in the large intestine of horses fed a high fiber or a high starch diet J. Anim. Sci. Oct;80(10):2600-2609

Nerlich HK, Koler R, Powell E and Williams TL (2018) 498 Saccharomyces cerevisiae supplementations effect on fiber digestibility in equine J. Anim. Sci. Apr;96(2):266

Newbold CJ, Wallace RJ, Chen XB and McIntosh FM (1995) Different strains of Saccharomyces cerevisiae differ in their effects on ruminal bacterial numbers in vitro and in sheep J. Anim. Sci. Jun;73(6):1811-1818

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