Probiotic potential and antioxidant, antidiabetic, and anticancer activities of goat milk-derived lactic acid...

Raw goat milk was explored as a source of lactic acid bacteria (LAB) with potential probiotic properties. Following 16S rRNA gene sequencing, Lactiplantibacillus plantarum PP101-STR and Lactococcus lactis PP104-STR were selected for further probiotic assessment. L. plantarum PP101-STR exhibited broad antagonistic activity against both Gram-positive and Gram-negative pathogens, especially Salmonella enterica ATCC 13312 and maintained high viability (> 83%) under simulated gastric conditions (pH 2.0-3.0) and bile salt exposure. This strain also demonstrated high cell surface hydrophobicity, along with strong auto-aggregation and co-aggregation capacities, which were associated with significantly enhanced adhesion to Caco-2 and HT-29 cell lines and effective competitive exclusion of pathogenic bacteria (p≤0.05). In addition, L. plantarum PP101-STR displayed strong antioxidant activity, as determined by total phenolic content, FRAP, DPPH, and ABTS assays, exceeding that of L. lactis PP104-STR. Its cell-free supernatant (CFS) exhibited notable α-glucosidase and α-amylase inhibitory activities, indicating potential for glucose regulation. Antiproliferative evaluation revealed that L. plantarum PP101-STR markedly suppressed colorectal cancer cell growth in a dose-dependent manner. Importantly, low lactate dehydrogenase release (8.11-8.86%) and maintained viability in MRC-5 cells indicated minimal membrane damage and low cytotoxicity toward normal cells, supporting a non-lytic mechanism potentially involving apoptosis-related pathways. On the basis of the present finding, L. plantarum PP101-STR demonstrates strong probiotic potential and multiple biologically relevant activities in vitro, supporting its further investigation in applications related to intestinal health.