Enterococcus Faecium in Pet Foods

Enterococcus faecium is a species of bacteria that has been characterized as part of the normal gastrointestinal microbial flora in animals and humans. It is a naturally occurring bacterium that grows in human and animal intestinal contents. They have been colonizing G.I. tracts of living creatures for eons and are here to stay. There's no way to "make them go away." Depending on the composition of a human diet or an animal ration, up to 100 million (1 x 10^8 ) colony forming units (CFU), or live bacteria, have been isolated per gram of fecal material. Thus, it naturally constitutes a major population in the gut. Bacteria are essential in the gastrointestinal tract. Although enzymes are excreted by humans and animals to digest foods, a considerable portion of consumed dietary ingredients are broken down by the action of intestinal microflora (bacteria).

To date, there have been no well-documented and characterized cases of disease attributed to E. faecium infection in animals (Devries and Pot, 1995). In fact, there are numerous studies published in the scientific literature that demonstrate effectiveness when Enterococcus faecium probiotic cultures are fed to livestock. In one particular calf study, calves were fed a negative control diet (no probiotics or growth-promoting levels of antibiotics), a diet containing a culture of Enterococcus faecium, or a diet containing the familiar growth-promoting antibiotic zinc bacitracin. Results from the study clearly demonstrated that both the probiotic culture of E. faecium and the zinc bacitracin diets performed equally well, and both treatments significantly out-performed the performance of the negative control diet. In light of these results, might not the probiotic culture accomplish the same result on the natural intestinal microflora as low-level feed antibiotics, shifting microbial population that favor enhanced performance, only without inducing antibiotic resistance? These cultures are delivering what the medical community has requested of the animal feeding industry – cost-effective performance without the use of antibiotics.

In another study with dogs, feeding a culture of E. faecium statistically significantly increased the serum titres (levels of circulating antibodies) to antigens contained in common dog vaccines, when compared to controls that were not fed the E. faecium probiotic culture. In dairy cattle, feeding live yeast and two strains of Enterococcus faecium to fresh cows increased dry matter intake, milk yield, and milk protein content as compared to negative control cows. There are countless other studies showing the benefits of feeding probiotic cultures of E. faecium to livestock, all without incident. These products increase feed costs when fed to livestock. Thus, in order to justify their use, economics dictate that the return for their use must exceed their input cost. Probiotic cultures of E. faecium are doing just that. No farmer is going to throw money away on useless (or dangerous) feed additives! Furthermore, Enterococcus faecium has been reviewed by the European Union and has been granted the status of an approved, safe probiotic.

Enterococcus faecium have been used as a human probiotic for more than 25 years. More recently, Sarantinopoulus et al. (2002) published a paper describing the benefits of using Enterococcus faecium strains as adjunct cultures in the making of feta cheese for human consumption. Leroy et al. (2003) studied the effects of adding a strain of Enterococcus faecium that was a natural isolate from cheese as a co-culture for the production of cheddar cheese. This bacterium was used because of its ability to inhibit the growth of Listeria monocytogenes, an extremely important food-borne pathogen. Hugas et al. (2003) reported that species of enterococci were used in processed meat fermentations for years. "Despite the concern about pathogenicity of enterococci, recent studies point out that food and meat enterococci, especially Enterococcus faecium, have a much lower pathogenicity potential than clinical strains." The authors stressed the benefits of the control of Listeria monocytogenes in sliced, vacuum-packed cooked meat products when Enterococcus faecium strains were used. There are countless other papers in the literature supporting the use of Enterococcus faecium probiotics in humans. Carefully selected and researched strains of Enterococcus faecium are safe and effective probiotics. One must keep in mind that not ALL Enterococcus are the same.

Devries and Pot reported in 1995 that Enterococcus faecium had received recent attention in the scientific literature. Increasing reports had surfaced describing an increase in the incidence of nosocomial infections in humans due to some strains of Enterococcus faecium that have become resistant to the antibiotic vancomycin. By definition, nosocomial infections are those infections "obtained while admitted to a hospital." But again, these infections have only been identified in long-term antibiotic therapeutic situations and in patients hospitalized with debilitating disease. Since that time, the medical community has designated these types of infections as VRE or vancomycin-resistant enterococcal infections.

  1. Enterococcus faecium is a normal healthy G.I. tract bacterium that constitutes an integral part of the intestinal microflora for most living creatures, including man. It cannot be removed from the environment and will continue to be a portion of the intestinal microflora.
  2. As the world community continues to demand that animal food products are produced with no antibiotics whenever possible, probiotics are going to play an increasingly greater role in the future.
  3. Carefully selected and researched strains of Enterococcus faecium are well-documented as safe and effective probiotics. They have been proven safe and effective in humans and livestock and have been recognized as such in the European Union, the United States, by the FDA, AAFCO, and in other countries as well.
  4. Although certain clinically challenging strains of Enterococcus faecium have been identified, their existence has been attributed to indiscriminate use of antibiotics in humans and animals, and such strains often turn into outbreaks, spreading rapidly when proper hospital sanitation procedures are lacking.
  5. The medical community has supported the use of beneficial probiotic cultures in humans. Despite the literature citations listed here, no authors in the volumes of research papers describing this problem have ever mentioned that these pathogenic strains of Enterococcus faecium were associated with the feeding of E. faecium as a probiotic, nor have they called for the prohibition of probiotic use.
  6. Wysong has used this probiotic culture for some 30 years and tens of thousands of humans and animals have benefited, not been harmed.


If you type Enterococcus faecium into a search engine and click a search result at random, you"ll inevitably see a few messages of caution. However, it "s important to note that there are variants, or strains, within the bacterial species – something that may not be immediately clear while performing cursory research. Certain strains within a given microbial species can be virulent while others may be benign or beneficial. Such is the case with Enterococcus faecium. The strains of Enterococcus faecium used in probiotic supplements today are the non-pathogenic varieties that provide health benefits.

E. faecium has long been recognised for its probiotic benefits and is widely used around the world. One of the major benefits of E. faecium is that it is uniquely suited to survive the digestive process and flourish in the gut. It promotes a balanced gut environment by competing for resources that harmful organisms would otherwise consume and use to grow. It also competes with harmful organisms for adhesion sites – areas on the surface of cells to which other cells and molecules can bind. Hence, this "multitasking " strain is commonly found in human and animal probiotic supplements.

E. faecium is accepted for use in animal feed by the Association of American Feed Control Officials (AAFCO) as a direct fed microorganism, provided the microorganism is non-toxigenic.

The EU is focused on demonstrating that the strain is safe and that safe strains can be differentiated from those that cause nosocomial infections in hospitals and possess AMR genes. The EU Commission, EFSA and the EU food and feed industries recognise that E. faecium, other lactic acid bacteria and Bacillus spp. are present in fermented foods, food supplements and pharmaceutical preparations. In the feed industry, they can also be used as feed additives, including fermented feeds such as silages.

As you can see, the potential benefits of E. faecium are significant. It can alleviate diarrhea, boost immune functions, and even help to deal with common contaminants in store-bought food. Research is ongoing for the benefits of probiotics in animals, but there is already sufficient data to support the potential benefits of E. faecium as a probiotic supplement for cats and dogs.

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