Effects of dietary fructooligosaccharide on selected bacterial populationsin feces of dogs

Objective-To evaluate fecal concentrations of selected genera of colonic ba cteria in healthy dogs, and to investigate effects of dietary fructooligosa ccharides (FOS) on those bacterial populations. Animals-6 healthy adult Beagles. Procedure-Dogs were randomly assigned to 2 groups of 3 and fed an unsupplem ented diet for 370 days. After 88 days, fecal samples were collected. Anoth er fecal sample was collected from each dog 282 days later. Group A then re ceived a diet supplemented with FOS, and group B continued to receive the u nsupplemented diet. Twenty-eight to 29 days later, fecal samples were colle cted. Diets were switched between groups, and fecal samples were collected 31 and 87 days later. Concentrations of Bifidobacterium spp, Lactobacillus spp, Clostridium spp, Bacteroides spp, and Escherichia cell in freshly coll ected feces were determined. Effects of diet and time on bacterial concentr ations were compared between groups. Results-Bifidobacterium spp and Lactobacillus spp were inconsistently isola ted from feces of dogs fed either diet. Sequence of diet significantly affe cted number of Bacteroides spp subsequently isolated from feces, but diet h ad no effect on numbers of Clostridium spp or E coli. Conclusions and Clinical Relevance-Some genera of bacteria (eg, Bifidobacte rium) believed to be common components of colonic microflora may be only sp oradically isolated from feces of healthy dogs. This deviation from expecte d fecal flora may have implications for the effectiveness of supplementing diets with prebiotics.