ACTIVE INGREDIENTS

Here’s a quick look at the types of active, “living” ingredients you may see listed on a probiotic product for horses:

Lactobacillus is a genus of anaerobic, rod-shaped, non-spore-forming bacteria that help convert sugars into lactic acids. These bacteria are the most common probiotic found in food such as yogurt. Common species included in probiotic supplements include plantarum, casei, reuteri and acidophilus.

Enterococcus is a large genus of spherical-shaped bacteria capable of living in oxygen-rich and oxygen-depleted environments. Although useful in the digestive tract, when Enterococcus bacteria spread to areas other than the gut, they can cause troublesome infections. There are at least 17 different species of Enterococcus; two you’ll commonly see in probiotic products are faecium and lactis.

Bifidobacterium is a genus of non-aerobic, y-shaped bacteria that are ubiquitous in the digestive system of mammals. It is the most common bacteria in the gut biome of infants. These bacteria ferment carbohydrates, producing thiamine, riboflavin, vitamin B6 and vitamin K in the process. Species you may see included in probiotic products include longum and niger.

(Some labels may not list these bacteria individually, using instead only a general description of “lactic acid bacteria.”)

Saccharomyces is a genus of fungi that contains may yeasts—including the S. cerevisiae, commonly known as baker’s yeast. A specific strain of this yeast, Saccharomyces cerevisiae var. boulardii is often included in probiotic products. It is thought to bind to pathogens and toxins in the gut, effectively neutralizing their effects. There is scientific evidence that it helps treat antibiotic-associated diarrhea and prevents travelers’ diarrhea in humans.

Finally, enzymes derived from two specific aspergillus fungus species— A. oryzae and A. niger— are used in some probiotics products for horses. These enzymes, which break down proteins and carbohydrates, are commonly used in probiotic products for cattle and other livestock and in other agricultural applications. Although some aspergillus fungi are associated with lung and other infections in susceptible individuals, enzymes from these two species are included on the Food and Drug Administration’s Generally Recognized as Safe (GRAS) list.