Abstract
Background
There is increasing evidence that gut microbiota is associated with cardiovascular health. In this exploratory study, the 16 S rRNA amplicon sequencing was employed to investigate the composition and differential abundances of bacterial gut microbiota of dogs at different stages of myxomatous mitral valve disease (MMVD): dogs with congestive heart failure (CHF, n = 38), dogs in the preclinical stage of the disease (non-CHF, n = 23) and healthy controls with no apparent heart disease (n = 17). Flow cytometry was performed to quantify T lymphocytes and their subtypes, as well as monocytes, natural killer (NK) cells and B lymphocytes. Concentrations of selected chemokines, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) were also measured. Correlation analysis was performed between immunological parameters and bacterial taxa of the gut microbiota.Results
Alpha diversity did not differ significantly between the study groups; however, several differentially abundant taxa were identified. Escherichia/Shigella was overabundant in the CHF group and showed a positive correlation with activated T lymphocyte levels, whereas Megamonas was overabundant in the control group and was negatively correlated with monocytes and NT-proBNP levels. Lachnospiraceae was overabundant in the non-CHF group.Conclusions
These findings suggest that dogs with varying severity of heart disease differ in gut microbiota composition. The observed associations between microbiota profiles, immunological parameters and disease status indicate potential microbiome-immune interactions in disease progression.