• The Role of Gut Microbiomes in Breast cancer
  • Aref Yarahmadi,1,* Hamed Afkhami,2 Parisa Sepahvand,3
    1. Department of Biology, Khorramabad branch, Islamic Azad University, Khorramabad, Iran
    2. Department of Medical Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran
    3. Department of Biology, Khorramabad branch, Islamic Azad University, Khorramabad, Iran


  • Introduction: Breast cancer (BC) stands as the prevailing form of invasive cancer among the female population worldwide, impacting approximately one out of every seven women throughout their lives. In the year 2022, a considerable number of women, amounting to around 287,850 individuals, were diagnosed with BC. Furthermore, an additional count of approximately 51,400 women were diagnosed with the specific condition known as breast ductal carcinoma in situ. BC presents itself as a disease with diverse characteristics and complexities, exhibiting significant heterogeneity between individual tumors as well as within tumors themselves. Research on risk factors for cancer has demonstrated that microorganisms can play a role in the progression of cancer in approximately 15 to 20 percent of instances. The microbiome present in our gastrointestinal tract possesses the ability to generate various metabolic substances that safeguard the equilibrium of the host. However, in cases of an imbalance in the gut flora, these microorganisms can also generate harmful molecules that have the potential to induce inflammation and the development of cancer. In this review article, we discuss the role of gut microbiota in BC. The gastrointestinal tract environment is known as an intricate ecosystem called the gut microbiota, consisting of various microorganisms such as bacteria, archaea, fungi, viruses, and protozoa. Increasing evidence suggests that the microbial community residing in the gastrointestinal tract is of significant importance to the overall human health. Moreover, when this community is disrupted and its balance is disturbed, it has been linked to numerous abnormal physiological processes.
  • Methods: Read more than 20 articles from 2020 onwards in the field of the gut microbiome and its role in modulating developing and treating breast cancer.
  • Results: Studies show that gut microbiota plays a role in BC. Also, the regulation of microbiota may help to predict the risk of BC. Intestinal metabolites have potential anticancer activity against BC. The potential anticancer effects of butyrate, a short-chain fatty acid, have been investigated in various cancer types, such as BC. Its ability to inhibit cancer growth has been observed through diverse molecular pathways. Similarly, Nisin a type of bacteriocin, has displayed a variety of anticancer characteristics, particularly about cancers of the gastrointestinal tract. Though the evidence is limited, there is some support for its potential application in the treatment of BC. Comparatively, in recent investigations, inosine, a naturally occurring purine nucleoside, has exhibited potential as a natural agent for combating cancer, even though its comprehensive exploration in this context remains incomplete. Moreover, recent research has indicated that the effectiveness of conventional chemotherapeutic agents can be affected by metabolites produced by gut microbiota, thereby suggesting the potential integration of these metabolites into combination therapies. Other studies showed that patients with BC and benign breast lesions have significant changes in the gut microbiota. Porphyromonas and Peptoniphilus are more abundant in BC patients, while Escherichia and Lactobacillus are more abundant in patients with benign breast lesions. Microbiota can affect estrogen levels and increase BC. Knowing the gut microbiota can lead to new treatments.
  • Conclusion: Throughout numerous studies, substantial evidence has been accumulated which substantiates the essential contribution of the intestinal microbiome in safeguarding overall well-being and averting detrimental transformations, such as the development of cancer. BC continues to pose a severe health risk worldwide, and existing approaches to treating breast tumors are encumbered by various limitations and resistance to therapy, thereby constraining their effectiveness in therapy. While there is still much to comprehend regarding the correlations between gut microbiota and BC, the disruption of the gut microbiota has been acknowledged as a pivotal factor in the inception, advancement, evolution, and spread of breast carcinoma. This issue requires more research and more comprehensive clinical studies to determine more precise connections and more specific mechanisms between the gut microbiome and BC.
  • Keywords: Breast Cancer, Microbiome, Microbiota, Metabolite