Cachexia and Gut Microbiota in Patients With Breast Cancer Receiving Home Care

This study aims to evaluate the possible association between cancer cachexia and Gut Microbiota (GM) in patients with Breast Cancer (BC) cared at home. Cancer cachexia is a multifactorial condition causing weight loss, muscle loss, and reduced physical strength in people with cancer. Moreover, the study will also analyze whether different stages of cachexia are linked to changes in the GM. The study will also explore whether a supplementation with a probiotic mixture for twelve weeks is associated with changes in the GM and participants' nutritional and clinical condition. The effect of the probiotic mixture (experimental group) will be compared with a placebo (control group) to evaluate whether changes in the GM and in cachexia-related measures differ between the two groups. Participants will: * Provide blood, stool, and urine samples to study the GM and biological markers. * Answer questionnaires about symptoms and quality of life. * Undergo assessments of nutritional status and body composition. Participants eligible for the intervention will take either a probiotic mixture or a placebo for twelve weeks. All study procedures will take place during home visits as part of the participants' regular home care program.