Once thought to be sterile, **blood is now recognized to contain bacterial DNA**, and a study led by **E. Scarsella and colleagues** brings this discovery into veterinary science. The team examined **37 dogs—18 healthy and 19 with gastrointestinal disease**—to compare bacterial communities in both blood and feces. Their goal: to understand whether blood microbiome patterns could indicate disease presence or progression.
Samples underwent **16S rRNA gene sequencing**, targeting the V3–V4 regions, followed by taxonomic and statistical analysis. The results showed that both **alpha (within-sample) and beta (between-sample) diversities** were significantly different between healthy and sick dogs for **both blood and fecal microbiomes**. Principal coordinates analysis confirmed **clear separation between the groups**, pointing to a consistent biological difference linked to health status.
Interestingly, some bacterial taxa appeared in both the **blood and gut microbiomes** of diseased dogs, suggesting **possible bacterial translocation** from the intestines to the bloodstream. This observation supports the hypothesis that certain gastrointestinal conditions may allow microbes or their DNA to escape the gut barrier—a phenomenon with diagnostic and possibly therapeutic implications.
These findings offer early evidence for a **core blood microbiome** in healthy dogs, which could one day serve as a **non-invasive biomarker** for monitoring gastrointestinal disease. However, the study’s authors caution that further research is necessary to determine the **origin and viability of the bacteria in the blood**, as well as their relevance to clinical outcomes.
As veterinary diagnostics evolve, the characterization of the **blood microbiome in dogs** may join the growing toolkit for **early disease detection**, contributing to improved care and prevention strategies for canine patients.
Source: E. Scarsella, G. Meineri, M. Sandri, H. H. Ganz, and B. Stefanon. Published in Veterinary Sciences, Volume 10, April 1, 2023.
