Fig. 1

Paired sample α-diversity changes during chemotherapy. a Observed species as a measure of bacterial richness and b Shannon diversity index as a measure of bacterial diversity. Pre-chemo: baseline samples (prior to chemotherapy), Post-1: 7–12 days post start of chemotherapy, Post-2 at the end of one chemotherapy cycle (median 21 days after chemotherapy). * = p < 0.05; ** = p < 0.01, performed Wilcoxon matched pairs signed rank test of 19 paired subject samples