Fig. 8

a. Pairwise Bray-Curtis distances for the mock community (MC, dataset 1, Additional file 4: Table S3), standardized sample (SS, dataset 5, Additional file 8: Table S7), and healthy adult (HA, dataset 6, Additional file 9: Table S8) group. Each box represents the interquartile range while the whiskers represent 1.5 times the interquartile range. Points outside the whiskers represent outliers. The number of pairwise distances for each group is indicated over the boxes. b. Multidimensional scaling (MDS) plot showing clustering of 25 samples taken from 5 healthy adult volunteers (dataset 6, Additional file 9: Table S8). Sample origin is indicated by color (individual 1–5). The stress value of the MDS model was 13.2%, indicating a good fit. c. Pairwise Bray-Curtis distances for the 15 samples sequenced using 2 different library preparation methods (dataset 7, Additional file 10, Table S9). The leftmost box shows distances between identical samples (P = paired), while the box on the right shows the distances for non-identical samples (UP = unpaired). d Multidimensional scaling plot showing clustering of the 15 samples sequenced using 2 different library preparation methods (dataset 7, Additional file 10, Table S9). Paired samples, i.e., identical samples sequences using different techniques, are joined by black lines