[Dr Lee]

I vaguely remember writing something about dog and human probiotics being different. Here is an excerpt from a lecture regarding probiotics. Let me know if this answers your questions. Short answer is most species have different flora especially an omnivore versus a carnivore versus a herbivore. The farther the species difference, the most likely farther the flora will be.

Take care.

-Dr. Lee

Prebiotics/Probiotics: Are They Any Use?
British Small Animal Veterinary Congress 2006
M.L. Chandler, DVM, MS, MACVSc, DACVN, DACVIM, DECVIM, MRCVS
Hospital for Small Animals, Easter Bush Veterinary Centre
Roslin, Midlothian

"Introduction

The types and ratios of bacteria in the intestinal tract impact on the health of an animal. Probiotics are live microbial feed supplements that benefit the host by increasing the ratio of normal 'healthy' intestinal microorganisms to the pathogenic species. Prebiotics are generally complex carbohydrates, such as fructooligosaccharides (FOS) that are fermentable, promote beneficial intestinal bacterial growth, and are meant to decrease the growth of pathogenic bacteria.

Synbiotics are a combination of both pro-and prebiotics. The prebiotic aids in the establishment of the probiotic organism in the complex colonic environment.

Probiotics

The microbes used in probiotics are non-pathogenic organisms, such Bifidobacterium or Lactobacillus, or non-bacterial organisms such as Saccromyces spp. Criteria for probiotic organisms include resistance to low gastric pH, adherence to intestinal mucosa, ability to proliferate and colonise the colon, activity against pathogenic microorganisms, and modulation of the immune system. They must also have no pathogenic, toxic, mutagenic or carcinogenic effects. The proposed benefits of probiotics include increased competition against pathogenic species of bacteria, reduction of bacterial translocation, and production of antimicrobial products.

The intestinal bacterial populations of humans, cats and dogs vary considerably. In humans, Bifidobacterium spp. are the most significant microbial barrier to infection, while dogs have fewer of these than humans, and they are isolated only intermittently from cats. Because of these variations, it is thought that probiotics should be derived from the species in which they are to be used.

In humans, there is evidence that intestinal bacteria are important in the pathogenesis of inflammatory bowel disease (IBD), so the study of probiotics has been a major area of emphasis. In genetically engineered mice used to study IBD, preliminary evidence indicates that Lactobacilli inhibit inflammation and also prevent development of colonic adenocarcinoma (a consequence of severe Crohn's disease or ulcerative colitis in humans). Trials have also shown that probiotics in people with Crohn's disease resulted in reduction in steroid therapy in 75% of the cases. There have been few controlled studies in dogs or cats with IBD, and the anecdotal evidence is equivocal. However, they may be useful if the appropriate concentrations and species of microbes are used in probiotic products intended for dogs and cats (e.g., in other words, not just adding yogurt to the diet!).

In humans, probiotics have been shown to be useful in the treatment of antibiotic-associated diarrhoea, probably by decreasing the growth of opportunistic pathogens such as Clostrdium difficile and Bacteroides fragilis. Studies of Lactobacillus acidophilus in dogs and in cats have shown a decrease in clostridia species, and another study in cats showed an increase in the elimination of Campylobacter organisms. Other potential benefits included modulation of the immune system and a decrease in red blood cell fragility.

Probiotics may encounter difficulties in surviving gastric acid and bile acids and their effect may be transient, i.e., when the treatment is stopped; the probiotic bacteria rapidly wash out of the intestine. In studies in dogs and cats the intestinal bacteria returned to the original concentrations and ratios within a week after stopping the probiotics. It is believed that these difficulties may be partly overcome by the use of prebiotics. "