Changes in the intestinal microbiota and systemic immune responses by dietary 1-kestose supplementation in healthy dogs

1-Kestose is a trisaccharide prebiotic that modifies immune responses in humans and rodents with allergic diseases by altering the intestinal microbiota. In the present study, we examined the effects of 1-kestose supplementation on the intestinal microbiota, peripheral lymphocyte subsets, and antibody production in healthy dogs. Fecal IgA levels and serum antibody titers against the rabies vaccine were not significantly affected by 1-kestose supplementation. In a flow cytometric analysis, the percentage of T cells among total lymphocytes decreased, whereas that of B cells increased in supplemented dogs. A metagenomic analysis of the intestinal microbiota showed that the proportion of Bifidobacterium increased, while that of Lactobacillus did not decrease in supplemented dogs. Furthermore, a quantification analysis using real-time polymerase chain reaction showed that the proportion of Bifidobacterium increased in supplemented dogs. These results suggest that 1-kestose supplementation induced modifications in the intestinal microbiota of dogs, which presumably enhanced the immune system. 1-Kestose may be a useful food material as a prebiotic for dogs.