Effects of dietary fiber and biotic supplementation on apparent total tract macronutrient digestibility and the fecal characteristics, metabolites, and microbiota of healthy adult dogs

Dietary fibers and biotics have been shown to support gastrointestinal health in dogs, but are usually tested individually. There is value in testing fiber-biotic combinations that are commonly used commercially. Therefore, this study was conducted to determine the apparent total tract macronutrient digestibility (ATTD) of diets supplemented with fibers or biotics and to evaluate their effects on the fecal characteristics, metabolites, microbiota, and immunoglobulin A (IgA) concentrations of dogs. Twelve healthy adult female beagle dogs (age = 6.2 ± 1.6 yr; body weight = 9.5 ± 1.1 kg) were used in a replicated 3 × 3 Latin square design to test three treatments: 1) control diet based on rice, chicken meal, tapioca starch, and cellulose + a placebo treat (CT); 2) diet based on rice, chicken meal, garbanzo beans, and cellulose + a placebo treat (GB); 3) diet based on rice, chicken meal, garbanzo beans, and a functional fiber/prebiotic blend + a probiotic-containing treat (GBPP). In each 28-d period, a 22-d diet adaptation was followed by a 5-d fecal collection phase. Fasted blood samples were collected on day 28. Data were analyzed using the Mixed Models procedure of SAS 9.4, with P