(A) Design scheme for fully factorial host taxon by diet mouse experiment (N = 10 laboratory mice or three wild mice per diet group). (B) Nonmetric multidimensional scaling (NMDS) ordination of Bray–Curtis dissimilarities showing changes for mice from day 0 (open circle) to day 28 (filled circle) by experimental groups (color). Composition varied by host taxon (p<0.001, R2 = 0.173, F = 64.255, permutational MANOVA), diet (p<0.001, R2 = 0.042, F = 15.427), and a host taxon by diet interaction (p<0.001, R2 = 0.020, F = 7.557). (C) Shannon index differed between host taxa on day 0 (p=0.011, Mann–Whitney U test). (D) Animals on reciprocal diets (DomH/WildD and WildH/DomD) but not control diets tended to move in opposite directions along Bray–Curtis ordination NMDS axis 1 from day 0 to day 28 (p=0.048 and p=0.25, respectively, one-sample Wilcoxon test). (E) At the end of the experiment, distance to the mean of the diet control at baseline (DomH/DomD and WildH/WildD) was lower for wild mice than for laboratory mice (p=0.048, Mann–Whitney U test). * indicates p<0.05, Mann–Whitney U test. Large circles are means; bars show standard deviations.