Grant: Travel Awards - Institute Community Support

Breast cancer is the most commonly diagnosed cancer worldwide. Although survival rates have improved, survivors often face long-term challenges, including the physical and emotional burdens of treatment. Preventing breast cancer could significantly improve population health. Estrogen plays a central role in hormone receptor (HR)-positive breast cancer, the most common subtype of breast cancer. Recent research has uncovered a potential connection between the gut microbiome-the collection of bacteria and other microorganisms living in the intestines-and estrogen regulation. Certain microbiome members can recycle estrogens and increase circulating levels, which may influence breast cancer risk. However, due to limited studies involving humans, this connection is not yet well understood. Our study investigates this connection by comparing the gut microbiomes of 70 postmenopausal women recently diagnosed with HR-positive breast cancer to those of 70 women without cancer. By combining detailed health and lifestyle questionnaires with blood and stool samples, we aim to identify specific bacterial and functional differences between the two groups. Advanced genetic sequencing of the stool samples will help us explore whether women with breast cancer have higher levels of estrogen-related bacteria. Overall, our study seeks to clarify the gut microbiome's roles in estrogen processing and its potential contribution to breast cancer risk. Understanding these connections could provide a foundation for microbiome-based prevention strategies, as the gut microbiome is modifiable by factors such as diet, lifestyle, and probiotics. Additionally, insights into the microbiome's influence on cancer treatment response may offer opportunities to enhance therapeutic outcomes for breast cancer patients.