So What the Heck is a PREBIOTIC and What Is It Good For?

Prebiotics For Dogs

Prebiotics (special fibres) , like probiotics (beneficial bacteria), and synbiotics (two is better than one), has taken the world of pet health and nutrition by storm as scientific studies continue to demonstrate the important roles they play in  supporting healthy gut microflora and promoting the optimum performance of various physiological and immunity processes in the body of dogs.

There are millions of bacteria that are normal inhabitants of the small and large intestines of animals. This microbial population promotes optimal digestion and metabolism, supports intestinal health and integrity,  stimulates immune system function, as well as supports the function of the nervous system (gut brain axis).

 This WellyWednesday blog article has a focus on the importance and benefits of  prebiotics for dogs. Sorry cats this is not about you!

 What’s Is Its Name?

The Food and Agriculture Organization (FAO) defines these name terms as:

Prebiotic - “nondigestible food ingredients that selectively stimulate the growth and activities of specific bacteria in the gastrointestinal tract and exert beneficial effects on the host.1

Probiotic - “living microorganisms which when administered in adequate amounts confer a health benefit on the host.2

Synbiotic - “a balanced combination of prebiotics and probiotics used together.”3

As you see from these definitions, prebiotics and probiotics are very differnt form one another and play different roles in the intestine and provide unique benefits to the gut microflora. While both promote intestinal health and wellbeing, probiotics introduce good bacteria into the gastrointestinal tract (GIT) of dogs while prebiotics act as ‘fertile ground’ for the resident good probiotic bacteria to gorw and survive better in the intestines.

Nutraceutical Supplements

Prebiotics, probiotics, and synbiotics are available in several forms. As supplements, they are collectively known as “nutraceuticals”. They can also be found in some therapeutic veterinary medical diets and typical pet store pet food brands.

The US Food and Drug Administration defines nutraceuticals as “nondrug substances produced in a purified or extracted form and administered orally to provide agents required for normal body structure and function with the intent of improving health and wellbeing.”

 Nutraceuticals Are NOT Pharmaceuticals

If you have tried looking for a probiotic for your dog you quickly come to realized that the option  of available choices can be very overwhelming. Unlike pharmaceuticals, nutraceuticals are not subjected to strict regulatory scrutiny. Thus, finding products that meet the required minimum performance standards of a good nutraceutical can be a real challenge.

 Qualities of a Good Prebiotic

  • It is not destroyed by enzymatic digestive juices
  • It can selectively increase the population and activity of beneficial probiotic bacteria
  • Provide health benefits
  • Stays in the intestine long enough for probiotic bacterial breakdown and fermentation to release beneficial short-chain fatty acids.

 Prebiotics Are Natural Beneficial Sugars and Fibers

Prebiotics are often associated with oligosaccharides, a unique type of carbohydrate. However, there are also non-carbohydrates, such as soluble fibers, that are classified as prebiotics.  Two of these soluble fibers are oligofructose and inulin.

Mannose oligosaccharides (MOS) undergoes quick fermentation in the colon to provide nourishment to the bacteria residing there. They are derived from the outer cell-wall membrane of bacteria, plants, or yeast.

Fructooligosaccharides (FOS) like inulin tends to ferment more slowly which can be beneficial for microflora that are living farther down the colon. Inulin is present in chicory root and Jerusalem artichokes.

Benefits of Fiber in the Diet

Basically all fiber helps with intestinal health. It modulates the intestinal transit time and helps absorbs fluid. Fiber also lowers intestinal pH as well as provides nutrients for good bacteria. One advantage that prebiotics have over probiotics is that they are not as fragile. Unlike probiotics, prebiotics are not sensitive to temperature, gut pH, or transit time through the gut.

Prebiotics and Gut Health

Prebiotic fibers are minimally digestible. Dogs and cats lack the enzyme that can break them down. However, the gut microflora are capable of digesting the fibers to produce beneficial short-chain fatty acids (SCFAs), the most common of which are acetate, propionate, and butyrate.   

These SCFAs that are produced through bacterial fermentation of the fibers are  important sources of energy for the cells of the colon (colonocytes). They also help lower the pH of the colon and stimulate the absorption of sodium and water from the colon. Butyrate or butyric acid is the primary energy source for colonocytes. It’s also thought to enhance the proliferation of normal cells while suppressing  the development of damaged transformed cells. 

“Prebiotics are key components for intestinal cells, which create a barrier in the intestinal tract. This lining is important because it helps to keep bacteria in the intestinal tract and doesn’t allow it to travel to other areas of the body.”6 When the lining of the intestine is not intact, proteins can get through the intestinal wall and will be recognized by the body as foreign invaders. The body responds by producing antibodies to combat these proteins, paving the way for digestive, skin, ear, eye, neurologic and other problems. This syndrome is better known as " Leaky Gut"

 Dog Probiotic Supplements Should Have Prebiotic Fiber 

  • The list of ingredients should include the type MOS or FOS or both fiber sources to support the probiotics.
  • The probiotic claims of the manufacturer should have research supporting  probiotic benefits claims.
  • The product should contain the stated EFFECTIVE quantities of PROBIOTICS for each species, NOT THE TOTAL BLEND and are expressed as CFU, Colony Forming Units
  • The product should promote normal intestinal microflora.

Considering that plants differ in the amounts of oligosaccharides and inulin that they contain, simply adding fiber to your dog’s diet won’t guarantee that your pet will benefit from prebiotic effects. The benefits that will be reaped will highly depend on the types of fibers that are found in the prebiotic.

Giving a good quality probiotic and prebioticto your canine buddy is one of the sure-fire ways to  support a healthy intestinal environment with a happy beneficial bacterial population.


  1.  Pan XD, Chen FQ, Wu TX, Tang HG, Zhao ZY. Prebiotic oligosaccharides change the concentrations of short-chain fatty acids and the microbial population of mouse bowel. J Zhejiang Univ Sci B 2009;10(4):258-263.
  2. Weese JS, Arroyo L. Bacteriological evaluation of dog and cat diets that claim to contain probiotics. Can Vet J. 2003;44(3):212-216
  3. Marks S. Probioticsnot just for people anymore. Proceedings of the 2017 Western Veterinary Conference, Las Vegas, Nevada.
  4. Steiner JM. Understanding the benefits of prebiotics. dvm 360. July 1, 2009. Accessed November 6, 2018.
  5. Lerman A, Lockwood B. Nutraceuticals in veterinary medicine. Pharm J 2007;278:51.
  6. Tremayne, J. Prebiotics, Probiotics And Intestinal Health Accessed April 13, 2021.


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