Fig. 2

Imidazole propionate is associated with dysbiosis in heart failure. A Serum levels of ImP in heart failure (HF) and healthy controls (HC) is shown as box plots and dot plots. Statistical significance was tested using Wilcoxon tests. A multivariable linear regression model was fitted to estimate whether the difference remained after adjusting for age and sex (model estimates are shown below the plot). B Distributions of gene abundances based on Kyoto Encyclopedia of Genes and Genomes (KEGGs) for histidine biosynthesis, degradation, and transport in HC and HF are shown as box plots and dot plots. Statistical significance was tested using Wilcoxon tests. C Distributions of the dysbiosis index (material and methods) are shown for quartiles of serum ImP. Statistical significance was calculated using a Wilcoxon test and a linear regression analysis where ImP was modeled continuously (log₂-transformed) with age, sex, and BMI as covariates (model estimates for log₂(ImP) is shown below the plot). D Top bacterial species associated with serum ImP from a bootstrapped random forest analysis. The bacterial species’ ranks are indicated by how often they were selected in the bootstrap repetitions (material and methods). Red dots: elevated in HF; blue dots: decreased in HF. See also Additional file 2 Table S5