The intestinal microflora metabolize dietary nutrients into metabolites. Some metabolites are beneficial, such as short chain fatty acids which have key roles in energy use, modulating inflammation and the immune response. Gut bacteria can also produce trimethylamine N-oxide (TMAO), a compound associated with accelerated heart disease.
In heart failure, decreased cardiac output leads to reduced intestinal blood flow and edema. Under these conditions, bacterial composition of the gut and intestinal function change in ways that can accelerate inflammation and the progression of heart disease.1–5 Additionally, the decreased blood flow and intestinal function can lead to poor nutrient absorption and contribute to cachexia.
Numerous studies in people have linked heart failure with changes in the gut microbiome. Heart failure patients, for example, typically have reduced diversity and depletion of core intestinal microbiota.6
In a controlled dietary intervention study, Purina scientists showed that the gut microbiome of dogs is more similar to that of people, than the microbiomes of the pig or mouse.7
This finding suggests that studies of the human heart-gut axis may contribute insights that improve cardiac health in dogs, too.