Figure 4. Widespread effects of diet on relative abundances of microbe OTUs in perch and stickleback.

Rows represent different diet effects (proportion littoral carbon or trophic position) in each of the two host species. Each column in the heatmap represents one of the 566 abundant OTUs (averaging >0.01% relative abundance), arranged by taxonomic group (names of Classes are provided along the bottom of the figure). Thin vertical red bars indicate OTUs whose relative abundance decreases significantly (P<0.05) with the diet metric in a quasibinomial GLM for the focal host species. Blue bars indicate OTUs whose relative abundance increases with the diet metric. On the right side of the figure, we indicate the percentage of the abundant OTUs that exhibit significant main effects of diet within each host species. Asterisks indicate whether this percentage significantly exceeds the 5% expected from false positives (***P<0.001).