The expression of 221 genes was positively associated with the higher activity of Lactobacillus in ER-negative (ER-/HER2 + and triple-negative types) samples (r > 0.7, p < 0.05) including breast cancer biomarker genes PLA2G2E, HIST2H2BE, CRKL, and CCND1 (Table 3) and the expression of same genes was negatively correlated with the relative activity of Bacteroides (Table 3). The gene discussed is ESR1; the disease is breast cancer.