“…Previously, the prevailing scientific consensus was that breast milk was a sterile fluid. , However, modern scientific methodologies have revealed the presence of a diverse microbiota in breast milk. , For example, interesting beneficial microorganisms, such as Bifidobacterium animalis ssp. lactis Probio-M8 and Lacticaseibacillus rhamnosus Probio-M9, have been isolated from breast milk. , This aligns with the contemporary understanding of breast milk as a biologically active fluid that contributes to infant development. ,, The origin of these microbes is diverse and complex, involving interactions with the infant’s oral cavity, maternal dermis, maternal digestive tract, and other pathways. ,, While the microbial consortium within breast milk remains relatively consistent, it can be still modulated by various external determinants, such as maternal dietary habits, lifestyle patterns, and overall health. ,, These microbes play a crucial role in fostering a beneficial gut environment for the infant, thereby contributing to long-term health. , Additionally, the metabolites released by these microbes make breast milk an invaluable source of nutrients . For instance, short-chain fatty acids (SCFAs) like acetate, butyrate, and propionate have specific physiological roles in supporting gut health, modulating local immune responses, and energizing cells. − Certain microbial metabolites, such as bioactive peptides, prebiotics, and nucleotides, are essential for the infant’s nutritional uptake, immune regulation, and anti-inflammatory activities. ,, …”