Strategies to correct dysbiosis include administration of prebiotics and probiotics. Prebiotics include carbohydrates and fermentable fibers. After ingestion, they are fermented by intestinal bacteria to produce SCFAs, resulting in numerous positive benefits as described above. Probiotics are defined as live microorganisms that, when administered in sufficient quantities, confer a health benefit to the host. Probiotics are not regulated as drugs in the United States and, thus, undergo minimal regulatory scrutiny.
Objective evaluations have shown that all probiotics are not created equal. In one study, no evaluated food contained all the bacterial strains listed on the label, and 26% of tested foods did not contain live bacteria.9 Additionally, up to two thirds of probiotics labeled for animal use have failed quality testing.10 Thus, we recommend that only probiotics that undergo regular evaluations for content and viability by their manufacturers be prescribed. Other major considerations include the number of species and colony forming units (cfu) of bacteria, presence of prebiotics (such combination products are referred to as synbiotics), and use of flavoring agents. The ideal number of bacterial strains and cfu likely varies by indication, but higher doses are currently used for correction of active disease.11 Products with flavorings should probably be avoided when managing patients with food-responsive disease or inflammatory bowel disease (IBD).
Probiotics have been used in dogs and cats to correct dysbiosis associated with acute and chronic enteropathies. In placebo-controlled trials, administration of probiotics significantly shortened diarrhea secondary to acute gastroenteritis in dogs.12-13 Probiotic administration was also shown to significantly decrease the duration of diarrhea in cats in a shelter environment.14 In one open-label trial of cats with idiopathic chronic enteropathy, owners reported their cats had significantly improved fecal scores after synbiotic (Proviable®-DC) administration.15
One randomized controlled trial evaluated clinical and histologic response rates in dogs with moderate to severe IBD treated with either probiotics (11-22 billion cfu/kg/d) or combination prednisone (1 mg/kg/d) and metronidazole (20 mg/kg q12h) therapy.11 Although median time to remission was about 6 days longer in dogs receiving probiotics, the two groups had equivalent remission rates and histologic improvement. Excitingly, enhanced T regulatory cell function and normalization of dysbiosis 30 days after discontinuation of treatment were found only in dogs treated with probiotics.