Anti-Colon Cancer Effects of Lysate from Potential Probiotic Yeast Strains Derived from Human Breast Milk

Breast milk contains a diverse array of symbiotic microorganisms, including beneficial probiotics. While most research has focused on the bacterial composition of breast milk, the fungal community (mycobiota) has received limited attention. In this study, we isolated and evaluated yeast strains from breast milk, demonstrating the safety and probiotic potential of four strains through hemolysis tests, antimicrobial activity, tolerance to gastrointestinal conditions, aggregation, cell adhesion, and antioxidant activity assays. These yeast strains significantly inhibited the proliferation of pathogenic bacteria and showed strong antioxidant properties. Moreover, lysates from Rhodotorula mucilaginosa and Cryptococcus laurentii isolated from breast milk markedly inhibited the proliferation of colon cancer cell lines (HT-29 and SW620) and induced apoptosis by upregulating key apoptosis-related genes (caspase 3, caspase 9, and Bax), as well as autophagy-related genes (Beclin-1, LC3, and ATG5). This study provides valuable insights into the potential of breast milk-derived yeast strains for developing novel probiotic therapies for colon cancer treatment.