Gut Microbiota and Breast Cancer: The Dual Role of Microbes

Abstract

Breast cancer is the most frequently diagnosed cancer and also one of the leading causes of mortality among women. The genetic and environmental factors known to date do not fully explain the risk of developing this disease. In recent years, numerous studies have highlighted the dual role of the gut microbiota in the preservation of host health and in the development of different pathologies, cancer among them. Our gut microbiota is capable of producing metabolites that protect host homeostasis but can also produce molecules with deleterious effects, which, in turn, may trigger inflammation and carcinogenesis, and even affect immunotherapy. The purpose of this review is to describe the mechanisms by which the gut microbiota may cause cancer in general, and breast cancer in particular, and to compile clinical trials that address alterations or changes in the microbiota of women with breast cancer.

Keywords: androbolome; breast cancer; estrobolome; microbiome; microbiota.

Figure 1

Several proposed mechanisms to understand the microbial influence on cancer. ↑ means increment.

Figure 2

The gut microbiota affects cancer pathogenesis and the metabolism of chemotherapy drugs, conditioning both the response of cancer cells and the susceptibility of healthy cells. ↑ means increment; ↓ means decrease; ⱶ means inhibition.