Numerous diseases can affect the overall health of the gastrointestinal (GI) tract and disrupt the balance of enteric bacteria (bacteria which live within the gastrointestinal tract). Prebiotics used as a dietary supplement can help maintain a healthy GI tract and aid in restoring the balance between beneficial bacteria and pathogenic (disease-causing) bacteria within the gut.
Importance of Gastrointestinal Microflora to the Health of the Dog and Cat
The gastrointestinal tract plays several vital roles in maintaining the health of a dog or cat, including:
- digesting and absorbing nutrients
- eliminating waste products and other substances which could be harmful to the pet
- performing an endocrine function by secreting certain hormones, such as gastrin and cholecystokinin
- performing an immune function by preventing pathogenic organisms from entering the blood stream and lymphatic system
In order to adequately perform these functions, the gut relies on an extensive ecosystem comprised of more than 1000 different types of bacteria which live within the gastrointestinal tract. Changes in the types and numbers of bacteria which populate the gut can contribute to or cause disease for the dog or cat. Growth and activity of the beneficial bacteria which are found in the GI tract inhibit the growth and activity of the pathogenic enteric bacteria (such as Salmonella, E. coli, Clostridium difficile and others). These beneficial bacteria are known as probiotic bacteria.
Prebiotics Protect the Gastrointestinal Microflora and Help Maintain a Proper Balance
Prebiotics are nondigestible ingredients in the food which selectively stimulate the growth and activity of the beneficial bacteria which colonize the colon. Dietary fiber is the most commonly utilized prebiotic.
Prebiotic Fiber Sources in the Canine and Feline
Fiber in the diet of the dog and cat passes through the stomach and small intestines intact but is fermented by bacteria which reside in the large intestine. Fermentation products resulting from the action of the local bacteria in the large intestine include short-chain fatty acids (SCFA). These SCFAs:
- provide a source of energy for the cells which line the inside of the colon (colonocytes)
- maintain a normal electrolyte and fluid balance
- maintain normal intestinal motility
- prevent the overgrowth of pathogenic bacteria
- modulate intestinal inflammation
- help maintain the normal morphology of the colon
What Makes a Fiber Source a Good Prebiotic?
In order for a fiber to be utilized as a prebiotic in the dog or cat,
- the fiber must resist being degraded by stomach acid, enzymes and hydrolysis
- beneficial bacteria in the intestines must be able to ferment the fiber
- the fiber must selectively stimulate the beneficial bacteria to grow and become active
Fructooligosaccharides (FOS) as a Prebiotic for Dogs and Cats
Fructooligosaccharides (FOS) are a type of fiber source which meet the criteria for being a prebiotic in the dog and cat. Fructooligosaccharides have been demonstrated to increase the numbers of Lactobacillus bacteria (a beneficial probiotic bacteria) in the intestinal tract while simultaneously decreasing the numbers of pathogenic bacteria (Bacteroides, E. coli and Eubacterium) when fed as a dietary fiber source. These characteristics make FOS a good choice for a prebiotic food ingredient in the canine and feline.
Cellulose and beet pulp have also been evaluated as a prebiotic source of fiber for the dog and cat. While both had some success in increasing the number of Bifidobacterium animalis AHC7 strain bacteria (another probiotic bacteria) in the intestinal tract, beet pulp performed better than cellulose. However, feeding FOS resulted in better results than both the beet pulp and the cellulose.
Combining Prebiotics with Probiotics in the Dog and Cat
Prebiotic fiber sources, such as fructooligosaccharides, can be combined with probiotic bacterial products to further enhance the properties of both products. These combinations are known as synbiotics and can provide a double-pronged approach to achieving a healthy gastrointestinal tract with a well-balanced microflora comprised of beneficial bacteria.
Source:
Sanderson, Sherry Lynn; "Why "Biotics"? Using Prebiotics and Probiotics in Your Practice"; Practical Applications for Achieving Gastintestinal Wellness Conference Proceeding 2010, Supplement to Compendium: Continuing Education for Veterinarians, December 2009.
