In a breast cancer model, fermented soy milk beverage containing Lactobacillus acidophilus, Lactobacillus bulgaricus, Streptococcus lactis, or Bifidobacteria inhibited the growth of estrogen-receptor positive MCF-7 human breast cancer in mice, and this effect was mainly involved in the generation of reactive oxygen species [45]. Here, ESR1 is linked to breast cancer.