Evaluating the Association Among Changes in Gut Microbiome, Fatigue, and Chemotherapy-Induced Nausea in Early Stage Breast Cancer

This study is examining whether changes in the gut microbiome (the community of bacteria in the digestive tract) are linked to nausea and fatigue during chemotherapy in people with early-stage breast cancer. Understanding this connection may help develop ways to reduce these distressing side effects. **You may be eligible if...** - You have been diagnosed with early-stage breast cancer - You are scheduled to receive chemotherapy that has a moderate to high risk of causing nausea (emetogenic chemotherapy) - You are being treated at a Mayo Clinic site **You may NOT be eligible if...** - You have received prior chemotherapy for breast cancer - You have a chronic gastrointestinal condition (like Crohn's disease or IBS) - You have taken antibiotics recently (usually within 30 days) - You use probiotics regularly - You are pregnant Talk to your doctor to see if this trial is right for you.