Factors like diet and lifestyle affect the gut microbiome (a complex of bacteria and organisms in the intestines). Your microbiome can affect estrogen levels, which is a risk factor for hormone-receptor positive breast cancer. We are comparing the gut bacteria of women with and without breast cancer to explore how therapies targeting the microbiome, like probiotics, may be used as a tool to prevent breast cancer.

We will send you a screening survey (2 min) to determine eligibility for the study. If eligible, we will share a consent form and ask if you are willing to enrol. Participants will complete two online questionnaires on general health (15 min) and dietary history (45 min-1 hr). We will also collect blood and stool samples at two points in time, once upon entry to the study and again six months later. Study results will be shared with participants.