Background: The canine gut microbiota plays a critical role in establishing a healthy intestinal tract. In other species, colonization with an altered microbiota is associated with poor immune regulation in later life.
Objectives: To characterize the source of intestinal microbiota colonization and describe longitudinal changes during the first months of life. Animals: 70 puppies from 12 different litters were selected from a breeding facility.
Methods: Microbiota composition was analyzed by 16S rRNA gene sequencing using rectal swabs collected from puppies at 2, 14, 60, 90 days and 1 year of age. Oral, cutaneous, rectal, and vaginal swabs were collected from dams 24 hours prior to the scheduled parturition.
Results: Samples from 2-day-olds were more similar to the mother’s vaginal microbiota, suggesting the birth canal influences the colonization of dogs. However, when proportions were considered, the puppies’ microbiota differed from those of all other groups (p < 0.001). Microbial richness and diversity (ANOVA) and community structure (PERMANOVA) differed significantly among puppies at days 2, 14, 60, and 90. Samples from older ages were more similar to the maternal fecal microbiota (p < 0.05), indicating that the puppies’ intestinal microbiota had matured by 90 days of age.
Conclusion: The puppy gut microbiota undergoes changes and is more similar to that of adults by three months of age. The intestinal colonization of puppies is influenced by the vaginal microbiome of mothers. A better understanding of early-life colonization and associated changes may yield new insights into the pathophysiology of chronic inflammatory diseases, such as atopic dermatitis.
