Prebiotics, Probiotics, Antibiotics: What’s Bugging You?

It seems like all you hear about these days is prebiotics and probiotics. Television advertisements, food and drink packaging, supplements, all proclaiming that they are extra special because they contain prebiotics or probiotics or both.

First some definitions:

Prebiotics are soluble fibres that are used for food by the “good” bacteria in our intestines and the intestines of our furry companions. The digestion of these fibres by the bacteria gives rise to compounds such as volatile fatty acids (VFA’s) and vitamins, which have beneficial effects on the lining of the bowel and on the whole organism.

Probiotics are live bowel bacteria that are isolated and purified. They are the “good guys” who help digestion, keep out the “bad guys” such as the bacteria that contribute to or cause illness, and produce those beneficial VFA’s and vitamins so vital to the health of the animal. They can also colonize the outer genital tract and reduce the risk of bacterial bladder infections.
Often found in fermented foods such as yogurt, saurkraut and kimchi, these bacteria are grown commercially in pure or mixed cultures, then dried, powdered, encapsulated or mixed into food or beverages.
The very important thing to remember is that these little guys need to be ALIVE when they get to the lower bowel (colon) where they live and work. So they need to be alive when they are swallowed, stay alive through stomach acid and the digestive enzymes in the small intestine, and get to the large intestine where they can set up shop. Ideally they would become permanent residents there, having large families and restocking their own numbers.

Antibiotics on the other hand are chemical compounds that non-selectively kill or damage bacteria. They are a vast and growing spectrum of drugs, which have been overused to the point of serious resistance; many antibiotics are now ineffective for bacteria carried by the human and animal population. This means that some infections which were very easily treated 40 years ago are now requiring hospital stays and even causing deaths.

Unfortunately in the veterinary field, there has not been much research on the ability of probiotic cultures to survive and thrive where they need to be. There are two commercially available single-organism products (Purina’s Fortiflora TM, and Eukanuba Prostora TM) and two multi-organism products (Centaur AcuteCare TM, BeneBac TM) that have had clinical studies showing that they survive in the bowel and have measurable effects against diarrhea. There are several high quality formulas in the human supplement market such as Genestra’s HMF line, Thorne’s L. Sporogenes and S. Boulardii, and Bio-K+ TM. There are also dozens of other formulations sold over the counter in health food stores and pet stores, as well as foods that have been supplemented with probiotic cultures. Because of the fragility of many of these bugs, it is essential that they be aprropriately handled throughout processing, packing and transport. I am very selective about which products I use therapeutically, to ensure potency.

Prebiotics are much more robust, and do not have the same sensitivity to heat and processing, so they are gaining in popularity as food additives. Products such as inulin (chicory extract), apple and citrus pectin, FOS (fructo-oligosaccharides) and MOS (mannanoligosaccharides) are examples of probiotics. How much is enough? Too much can get the bowel bacteria “excited” and produce unwanted side effects such as gas and cramping. Helpful effects of prebiotics are similar to probitics, as they support the beneficial bacteria’s growth. They are also a source of  soluble fibre, which helps lead to satiety, keeps moisture in the bowel and regulates bowel movements.

In integrative veterinary medicine, probiotics are used not only for intestinal disorders such as diet or stress-induced acute diarrhea, and to balance antibiotic therapy. Probiotics can help repopulate the “good” bacteria around the urinary tract openings and prevent recurrant bladder infections. They can also help to heal the lining of the bowel in cases of “leaky gut syndrome” and reduce the overall allergy threshold, alleviating dermatitis and chronic ear infections in many patients with atopy (skin allergies). One more area where probiotics are used is in kidney disease, where certain probiotic strains can bind and eliminate toxins through the bowel, making the kidneys’ job easier.

If you think that your  pet would benefit from probiotic and/or prebiotic therapy, please contact me at

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