Lactiplantibacillus plantarum B isolated from breast milk improves functional properties and increases bioactive ingredients related to antihypertensive effects in fermented buffalo milk in vitro

Hypertensive disorders of pregnancy adversely affect maternal morbidity and mortality and preterm birth, and are associated with gut dysbiosis. Buffalo milk and its fermented products possess significant health benefits, including shaping the gut microbiome. Previously, probiotic-fermented buffalo milk, produced with a traditional yogurt starter and Lactiplantibacillus plantarum B ( L. plantarum B) isolated from the breast milk of healthy women in China, improved blood pressure in rats with pregnancy-induced hypertension. However, the mechanism of action behind the health benefits is largely unknown. To identify biological activity relevant to the cardiovascular system and associated bioactive ingredients, samples from buffalo milk that were unfermented, fermented with L. plantarum B, fermented with a traditional yogurt starter, or fermented with a mixture of L. plantarum B and a traditional yogurt starter, were analyzed using biochemical assays and non-targeted metabolomics. Buffalo milk that was fermented with L. plantarum B demonstrated significantly enhanced activities related to angiotensin-converting enzyme inhibition, antioxidant (2,2-diphenyl-1-picrylhydrazyl) scavenging, and cholesterol scavenging, compared with raw buffalo milk or that fermented with only a traditional yogurt starter (all p  < 0.05). Metabolomic analyses identified several significantly changed functional metabolites in L. plantarum B-fermented buffalo milk compared with raw buffalo milk, which strongly correlated with the changes in bioactivities. These findings demonstrate that L. plantarum B can be used to enrich buffalo milk with cardioprotective metabolites, which supports its potential as a dietary intervention for hypertensive disorders of pregnancy. This study provides a foundation for developing targeted functional foods to improve maternal cardiovascular health.