The study produced several useful findings.
Twenty-three species formed a core microbiome
Researchers identified 23 bacterial species that appeared consistently across the healthy reference population.
Together, those species represented approximately 75% of the faecal microbiome on average.
Examples included:
Peptacetobacter hiranonis
Megamonas funiformis
Prevotella copri
Turicibacter sanguinis
Collinsella intestinalis
and Blautia hansenii
Healthy dogs still differed substantially from one another
Although a common core could be identified, there was considerable variation between individuals.
No single host factor explained most of the microbiome.
Diet was the strongest measured predictor
Of the factors examined, diet explained the largest proportion of variation in overall microbiome composition.
Even then, it accounted for only around 5% of the observed variation.
Geographic region accounted for approximately 2.2%, body weight 1.8%, sex and neuter status 1.1%, and age 1.1%.
Body size mattered
Dogs of intermediate body weight had the highest microbiome diversity in some analyses.
Sixteen bacterial species were significantly more abundant as dog body weight increased.
Age was associated with specific bacterial changes
Several species, including Prevotella copri and Bacteroides coprocola, declined with age.
Escherichia coli showed the opposite relationship.
Diet changed which species were relatively abundant
Raw-fed dogs and kibble-fed dogs showed different species profiles.
For example, raw-fed dogs had greater relative abundance of several species including Bacteroides vulgatus and Enterococcus faecium.
Kibble-fed dogs had greater relative abundance of species including Collinsella intestinalis, Megamonas funiformis and Prevotella copri.
Importantly, these differences do not establish that one dietary pattern produced a healthier microbiome than another.
