Chemotherapy altered the fecal bacteriome over time. (A) Alpha diversity as measured by Shannon Index decreased as an effect of time, and was decreased between baseline and post-6 injections in the chemotherapy group but not the vehicle group. (B) This decrease was associated with an increase in Lactobacillus as an effect of time and was increased between baseline and post-6 injections in the chemotherapy group but not the vehicle group and (C) was negatively correlated to alpha diversity. (D) Weighted UniFrac distances (beta diversity) differentiated between chemotherapy and vehicle groups, and (E,F) biplots for Lactobacillus (black arrows) suggest that relative abundance of this genus drive differences across time, especially in the chemotherapy group. n = 6–10/group; *p < 0.05 repeated measures ANOVA for time; #p < 0.05 vs baseline.