The Intestinal Microbiome in Triple Negative Breast Cancer Treated with Immunotherapy

Inclusion criteria

• Age ≥18 years
• Female biological sex
• Newly diagnosed, previously untreated, histologically confirmed early triple-negative breast cancer
• Plan to initiate preoperative anti-PD-1 immunotherapy using pembrolizumab
• Overweight or obesity, defined as a body mass index >=25 kg/m2
• Ability to provide written informed consent
• Allow the collection and storage of biospecimens and data for future use

Exclusion criteria

• Active autoimmune disease
• Concomitant conditions that require the use of antibiotics (e.g., chronic sinusitis)
• Digestive disease disorders (e.g., irritable bowel syndrome, Crohn's disease)
• Currently pregnant, breastfeeding, or planning to become pregnant within the next 24 weeks
• Recent (within 90 days) use of glucocorticoids for more than 10 consecutive days
• Any other cardiovascular, pulmonary, orthopedic, neurologic, psychiatric, or other condition that, in the investigator's opinion, would preclude participation or successful compliance with the protocol
• Any other situation that, in the opinion of the investigator, would negatively impact subject safety or successful compliance with the protocol