Figure 1.

Neoadjuvant chemotherapy modulates breast tumor microbiota. Tumor 16S sequencing results were grouped by whether patient was treated with neoadjuvant chemotherapy before definitive surgery (n=15) or whether patient underwent surgery first (n= 18). A. Total bacterial load was quantified by 16S RT-PCR and graphed as 16S copies per uL of DNA. Neoadjuvant chemotherapy did not change total levels of bacteria within a tumor. B. Shannon diversity. Neoadjuvant chemotherapy significantly reduced the bacterial diversity within the tumor. C. Relative abundance of bacterial genera in different tumor samples is visualized by bar plots. Each bar represents a single tumor and each colored box a bacterial taxon. The height of a color box represents the relative abundance of that organism within the sample. “Other” represents lower abundance taxa. Approximately 25% of total tumor microbiota comprises of 105 genus level taxa with less than 1% proportional abundance. D. Primary breast tumors from patients that received neoadjuvant chemotherapy display no broad spectrum differences in bacterial phylum level proportional abundances. At the genus level, neoadjuvant chemotherapy treated tumors have elevated proportional abundance of Pseudomonas (E) and decreased levels of Prevotella (F) taxa when compared with untreated breast tumors. *p<0.05 and error bars show the min to max distribution.