Effect of dietary supplementation with fructo-oligosaccharides on fecal flora of healthy cats

Abstract Objective To investigate changes in the fecal flora of healthy cats after dietary supplementation with fructo-oligosaccharides (FOS). Animals 12 healthy, barrier-maintained, specific-pathogen-free-derived adult cats. Procedure Fresh fecal samples for quantitative and qualitative bacteriologic examination were collected from each cat after ingestion of a replete dry (basal) diet for a minimum of 8 weeks. The diet was then supplemented with 0.75% FOS, and another fecal sample was collected after 12 weeks. Results Mean ± SD fecal aerobic, anaerobic, and total bacterial counts (log 10 colony-forming units per gram of feces [CFU/g]) did not differ significantly between diets (8.3 ± 0.8, 9.2 ± 0.6, 9.4 ± 0.4, respectively, for the basal diet; and 8.4 ± 0.8, 9.7 ± 0.7, and 9.8 ± 0.7, respectively, for the FOS diet), although there was a trend for higher numbers of anaerobes and total bacteria associated with the FOS diet. Members of the genus Bacteroides, Clostridium perfringens, Escherichia coli , lactobacilli, and Plesiomonas shigeloides were the most prevalent bacteria isolated. Compared with samples from cats fed basal diet, there was a trend for increased mean counts of lactobacilli ( P = 0.02) and Bacteroides spp ( P = 0.05) after FOS supplementation, and a trend for decreased mean numbers of Escherichia coli ( P = 0.03) and Clostridium perfringens ( P = 0.08) to be associated with the FOS diet. Supplementation of FOS resulted in a median 164-fold increase in numbers of lactobacilli, 13.2-fold increase in Bacteroides spp, 98% reduction in numbers of C perfringens , and 75% reduction in numbers of E coli . Conclusions Supplementation of the diet with FOS resulted in alteration of the fecal flora of cats. ( Am J Vet Res 1998;59:436–440)