Fig. 3

Sparse partial least squares (sPLS) regression of immune parameters and intestinal bacterial taxa during HSCT. a Correlation circle plot for the first two sPLS dimensions with correlations displayed for > 0.2/< − 0.2. The two grey circles indicate correlation coefficient radii at 0.5 and 1.0. Bacterial operational taxonomic units (OTUs) are displayed as circles, and are colored according to the cluster they are affiliated with (cluster 1: blue; cluster 2: orange; cluster 3: grey). Variables projected closely to each other are positively correlated. Variables projected diametrically opposite from each other are negatively correlated. Variables situated perpendicularly to each other are not correlated. The variance explained by the OTUs is 4.12% on component 1, and 4.79% on component 2. The variance explained by the clinical variables is 16.1% on component 1, and 17.19% on component 2. b Clustered image map (CIM) of the first two sPLS dimensions, displaying pairwise correlations between OTUs (bottom) and clinical variables (left). Red and blue indicate positive and negative correlations, respectively. Hierarchical clustering (clustering method: complete linkage, distance method: Pearson’s correlation) was performed within the mixOmics cim() function based on the sPLS regression model. An overview of the OTU abundances in the individual samples is provided in Figure S3, and a list of the individual OTUs and their cluster-affiliation is provided in Table S3. c Loading plots of OTUs with maximum contributions on the first (left) and second (right) component, respectively. The bars are colored according to the cluster they are affiliated with. The family-affiliation for each respective OTU is indicated by color (for legend see b). Abbreviations of variables are the same as in Fig. 2