For decades, scientific research has focused on fighting "bad" bacteria in the body, primarily through the use of antibiotics.
Antibiotics are often effective at killing "bad" bacteria in the body, but unfortunately they are not without problems. For
example, antibiotics are not selective in the kinds of bacteria they kill; "good" bacteria are killed along with "bad" bacteria.
In addition, "bad" bacteria are becoming "super" bugs and developing resistance to many commonly prescribed antibiotics. Antibiotics
can also cause numerous adverse side effects.
More recently, there has been a shift away from fighting "bad" bacteria in the body in favor of promoting "good" bacteria
primarily through the use of the "biotics" which include prebiotics, probiotics and synbiotics. Promoting beneficial bacteria in the GI tract by using "biotics" offer
several distinct advantages over the use of antibiotics to kill bacteria. The "biotics" can be incorporated into the diet
and provide a proactive way of maintaining health on a daily basis, whereas antibiotics are generally used only after a problem
has occurred. "Biotics" can be used on a long-term basis without encountering the side effects seen with antibiotics, and
"biotics" are viewed as a more holistic approach to maintaining health in the animal than are antibiotics. A healthy bacterial
flora in the intestines is important for not only health of the GI tract, but overall health. "Biotics" enhance and support
a healthy bacterial population, whereas antibiotics disrupt this balance. The bacterial flora in the gut are so important
that they have a collective metabolic activity equal to a virtual organ within an organ and have been referred to as a forgotten
What are probiotics?
Probiotics are defined as (a) live (viable) beneficial bacteria, which upon ingestion in sufficient numbers (b) exert health
benefits to the host. It is very important that both parts of the definition are met in order to call a product a probiotic.
The gastrointestinal tract in dogs and cats
The gastrointestinal (GI) tract in dogs and cats is a very dynamic organ that performs numerous functions essential for health
and well-being. Critical roles of the GI tract include digestion and absorption of nutrients and elimination of potentially
harmful substances and waste products. In addition, the GI tract is the most voluminous immunologic organ in the body and
also functions as an endocrine organ.
Companion animals have extensive gastrointestinal bacterial ecosystems. For example, the mammalian digestive system contains
more than 1,000 different species of bacteria and comprises approximately 95% of the cells in the gastrointestinal tract.
The balance between the beneficial bacteria and the pathogenic bacteria have an effect on overall health of the animal. For
example, enteric bacteria contribute significantly to the function of the host's immune system as well as resistance to infectious
disease. Furthermore, changes in the composition of the intestinal flora can be associated with disease and may, in some
cases, be a precipitating factor. "Biotics" can be used to maintain a healthy gut flora.
Important characteristics of successful probiotics
Probiotics are a rapidly emerging area in veterinary medicine, and more and more companies are selling products labeled as
probiotics for dogs and cats. However, not all these products meet the definition of probiotics. How does the practitioner
know whether a product is worth spending their client's money on it? In addition to meeting the criteria for the definition
of a probiotics, any company selling a probiotic product for dogs or cats should be able to document that their product meets
the characteristics of a successful probiotic which include:
1. Stability of the product
2. The ability of the product to survive passage through the stomach and resist damage from bile salts as it passes through
the small intestines.
3. The ability of the bacteria to colonize the gut
4. The ability of the probiotic organism to ferment prebiotics
5. Species specificity
6. Antipathogen effects
7. Safety of the product
8. Clinical efficacy of the product for the intended species. This is one of the most important characteristics of any