The role of probiotics in veterinary medicine - prophylactic use and in conjunction with disease.

The awareness of probiotic therapy has increased in recent years. Many pet owners and veterinarians are now using probiotics successfully both to manage and prevent many different conditions. This article will present the scientific basis of probiotic use specifically focusing on dogs and cats.

The Intestinal Microflora

The gastrointestinal (GI) tract of all animals is home to several different microorganisms known as the microflora. The number of microorganisms in the GI tract is thought to be around 10¹², which is more cells than the entire rest of the body. The GI tract is sterile at birth but is almost immediately colonized by bacteria from the birth canal and the environment. Once the microflora is formed it is unique to the animal and generally remains stable over time. However, several factors can affect the microflora e.g. stress, diet, medicine and age (Kyffin, 2016).

The microflora is very important to the health of the host. The GI tract is the largest immune organ in the body and serves as a barrier of defence against invading pathogens (Vighi et al. 2008). Roughly, 70 % of the immune system originates in the digestive tract, and so a balanced microbial ecosystem is crucial for optimal health (Suchodolski and Simpson 2013). Dysbiosis is a term used to describe an imbalance in the microflora, and it is now a general perception that alterations in the microflora play an important role in various GI disorders. Dysbiosis can occur because of e.g. antibiotic usage, dietary changes (intolerance or indiscretion), gastrointestinal disease, stress or life-stage (Kyffin 2016). Symptoms associated with intestinal dysbiosis include diarrhoea, vomiting, weight loss and changes in appetite.

Presentation of Probiotics

The history of live microbial feed supplements dates back thousands of years. As early as 2500 B.C. wall paintings suggest the habit of inoculation of milk to induce fermentation (Fuller 1992). The understanding of the word “probiotic” as it is used today was not defined until 1989 by Fuller. He described probiotics as being: “a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance”.

Probiotics can be used to alter the intestinal microflora to a more favourable balance. Thus proving very helpful in cases of intestinal dysbiosis. Probiotics exert their effect in several ways, which can be divided into the following modes of action:

• Competition for nutrients and adhesion sites
• Alteration of the microbial metabolism
• Stimulation of the immune system
• Direct antimicrobial effect

(Fuller 1989 and Shah 2007)

Probiotics in veterinary medicine

The use of probiotics in veterinary medicine is growing. Many veterinarians are seeing great results when using probiotics not only when treating gastrointestinal disorders, but also for prophylactic purposes. Probiotics have proven helpful in providing preventative and supportive care for both humans and pets (Tuohy et al. 2003, Wynn 2009, Veir et al. 2007 and Grajek et al. 2005). They are useful in cases of antibiotic-associated diarrhea and in the prophylactic approach to diarrhea in dogs and cats housed in animal shelters (Shah 2007 and Bybee et al., 2011). Other studies have shown positive effects on the immune system e.g., puppies supplemented with E. faecium SF68 had a better response to the CDV-vaccine than non-supplemented did (Benyacoub et al. 2002). Similar positive effects on vaccine responses have also been shown in kittens. (Veir et al. 2007).

A new generation of Pet food

Based on the growing awareness on probiotics and their health benefits, a new group of pet foods has emerged – so-called functional foods. Functional foods are defined as: “foods that contain some health-promoting components beyond traditional nutrients” (Shah 2007). Functional foods are consumed as part of a normal everyday diet and are not classified as supplements (Grajek et al. 2005). One way to modify foods to become functional is by adding probiotics (Shah 2007).

Probiotic pet food should not be considered as a diet only meant for pets with some kind of GI disease, but a standard food with extra benefits. Thus it can be eaten on a daily basis by all pets. Probiotics contribute to the everyday wellbeing of the pets because it helps to keep the intestinal system balanced.

When providing nutritional supplements for pets, compliance is important. and many manufactures are producing pet foods containing probiotics. Since probiotics are not drugs, there are fewer regulations regarding their use as supplements and food additives. Various studies are reporting poor quality control with probiotic products. A significant percentage of products does either not contain the organisms or the number of organisms stated on the label, or they contain additional species (Weese and Arroyo 2003). Based on several tests and studies there seem to be a great difference in the quality of probiotic pet foods (Weese and Arroyo 2003 and Kazarjan et al. 2012). More control and regulation is needed for the manufacturing of probiotic products for pets, and especially veterinarians but also pet owners are advised to make available published evidence and experience into account when choosing probiotic diets.

By Therese G. Hosbjerg, DVM and Technical manager at Bacterfield GMBH

References

• Benyacoub J., Czarnecki-Maulden G.L., Cavadini C. et al. (2003): Supplementation of Food with Enterococcus faecium (SF68) Stimulates Immune Functions in Young Dogs. Nutritional Immunology, 133(4), 1158-1162.
• Bybee S.N., Scorza A.V. and Lappin M.R. (2011): Effect of the Probiotic E. Faecium SF68 on Presence of Diarrhea in Cats and Dogs Housed in an Animal Shelter. J Vet Intern Med. 25 (4), 856-860.
• Fuller R. (1989): A Rewiev – Probiotics in man and Animals. Journal of Applied Bacteriology, 66: 365-378.
• Fuller R. (1992): Probiotics: The scientific basis. Springer Science + Buisness Media, Dordrecht.
• Grajek W., Olejnik A. and Sip A. (2005): Probiotics, prebiotics and antioxidants as functional foods. Acta Biochimica Polonica, Vol. 52, No. 3, 665-671.
• Kazarjan A., Kabanova N. and Vilu R. (2012): Microcalorimetric Study of Extruded Dog Food Containing Probiotic Micro-Organisms. Advances in Microbiology, 2, 436-440.
• Kyffin J. (2016): The Role of Probiotics in Veterinary Medicine. International Animal Health Journal – Research and Development. Vol. 3, Issue 1, 46-49.
• Shah, N.P. (2007): Functional cultures and health benefits. International Dairy Journal, 17, 1262-1277.
• Suchodolski J. and Simpson K. (2013): Canine gastrointestinal microbiome in health and disease. Veterniary Focus, Vol. 23, No. 2, 22-28.
• Tuohy K.M., Probert H.M., Smejkal C.W. and Gibson G.R.: Using probiotics and prebiotics to improve gut health. Drugs Discovery Today, Vol. 8, No. 15, 692-700
• Veir J.K., Knorr R., Cavadini C. et al. (2007): Effect of Supplementation with Enterococcus faecium (SF68) on Immune Functions in Cats. Veterinary Therapeutics, Vol. 8, No. 4, 229-238.
• Vighi G., Marcucci F. et al. (2008): Allergy and the gastrointestinal system. Clinical and Experimental Immunology. 153 (Suppl. 1), 3-6.
• Weese J.S. and Arroyo L. (2003): Bacteriological evaluation of dog and cat diets that claim to contain probiotics. Can Vet J, Vol. 44, 212-216
• Wynn S. (2009): Probiotics in veterinary practice. JAVMA, Vol. 234, No. 5. Vet Med Today: Timely Topics in Nutrition, 606-613.