Figure 2: Log2 fold change in relative abundance of ASVs in the DEP treatment in comparison to the control. Cutoff for inclusion of ASVs in this plot was FDR (=Padj) < 0.01. Colors represent most specific taxonomic label.
𝛼-diversity of the gut microbiome
The number of observed ASVs did not differ between treatments (GLM with gamma distribution: F3,69 = 0.3008, P = 0.825;Figure 3A ). Pielou’s evenness differed between treatments (Kruskal-Wallis rank sum test: X 2 = 23.296, df = 3, P < 0.001; Figure 3B ). The DEP treatment had a significantly lower evenness than the other treatments (Dunn’s comparisons with Benjamini-Hochberg (BH) adjusted p-values: DEP vs. control P < 0.001, DEP vs. solvent control P< 0.001, DEP vs. brake dust P < 0.001; Figure3B ). Shannon diversity differed between treatments (Kruskal-Wallis rank sum test: X 2 = 14.642, df = 3, P = 0.002; Figure 3C ). The DEP treatment had a significantly lower diversity than the other treatments (Dunn’s comparisons with BH adjusted p-values: DEP vs. control P = 0.003, DEP vs. solvent control P = 0.001, DEP vs. brake dust P = 0.010; Figure 3C ). Faith’s PD differed between treatments (Kruskal-Wallis rank sum test: X 2 = 10.777, df = 3, P = 0.013; Figure 3D ). Faith’s PD in the DEP treatment was significantly higher than in the other treatments (Dunn’s comparisons with BH adjusted p-values: DEP vs. control P = 0.009, DEP vs. solvent control P = 0.009, DEP vs. brake dust P = 0.007;Figure 3D ).